Why was Yehudahs approach to saving Yoseph so different from that of Reuvens?
Why do the sages condemn those who find merit in Yehudahs tactics?
Reuven heard these words [the brothers’ plot to murder Yoseph] and tried to rescue him saying “Let’s not kill him.†And he said to them “Don’t commit bloodshed … “
— Bereishis 37:21,22
Don’t spill the blood of an innocent man
— Targum Yonasan ben Uziel ibid
Reuven responded and said “ didn’t I tell you not to commit a sin against the lad [Yoseph]? but you didn’t listen. Now a Divine accounting is being demanded for his bloodâ€
— Bereishis 42:22
And Yehudah said to his brothers: “What will we gain [ מה בצע] if we slay our brother and conceal his blood?â€
— Bereishis 37:26
And the greedy one desirous of gain [ובוצע ברך] blesses himself … in having infuriated HaShem
— Tehillim 10:4
Rabi Meir says: This passuk  [ובוצע ברך] refers to none other than Yehudah, for it is written, And Yehudah said to his brothers: “What will we gain [ מה בצע] if we slay our brother and conceal his blood?†So all who praise/bless Yehudah, the botzeia; infuriate [HaShem] …
— Sanhedrin 6B
There was a small city, with only a few inhabitants; and a great king came against it, surrounded it, and built great siege-works against it. Â A poor wise man was present in the city who, by his wisdom, liberated the city; yet no one remembered that poor man.
— Koheles 9:14,15
[The above passage is interpreted as referring to the milchemes hayetzer-man’s internal moral battle to exercise his free will properly. The “great king†refers to the yetzer hara-inclination to evil; while the “poor-wise†man represents the yetzer tov-inclination to good. The Gemara comments:] “At the time that the yetzer hara holds sway no one can even remember the yetzer tov.â€
— Nedarim 32B
Rabi Yehudah quoting Rav said “One should always busy himself with Torah [study] and Mitzvah [performance] even if he does so for ulterior motives for the result will eventually be that, from within the ulterior motives, he will [develop to] attain the level of [Torah study and Mitzvah performance] for its own sake.
— Nazir 23B
Both Reuven and Yehudah tried to dissuade their other brothers from harming Yoseph. But their diverse approaches are markedly different. Reuven is an ethicist exhorting the brothers to avoid sin and spilling the blood of innocents. Reuven appeals the better angels of their natures and argues, in effect, that virtue is its own reward and that they ought to do the right thing for its own sake. Yehudah is a pragmatist. His tactic to get the brothers to drop their murderous plan is “What’s in it for us? What do we stand to gain either monetarily (Rashi’s interpretation) or in terms of our fathers affection?â€Â There is no trace of a moral or halachic argument in Yeudah’s words.
The Izhbitzer explains that Yehudah based his approach on the psycho-spiritual dynamic revealed by the Gemara-Talmud; that “At the time that the yetzer hara holds sway no one can even remember the yetzer tov.†When the Divine Will chooses to test us It causes us to completely forget the severity of the prohibition and to put the moral repugnance of the sin out of our minds. HaShem designed the mechanism of bechirah chofshis-human free-will; to function such that, in the heat of the nisayon-test; when the yetzer hara asserts itself, none can even remember the yetzer tov. While enmeshed in the ethical challenge to reject evil and embrace good, exhortations for moral and ethical behavior, to do the right thing for its own sake, will fall on deaf ears. The time for understanding and internalizing the lessons of the superiority of good over evil and that virtue is its own reward is pre-need. In the heat of the moment of trial the inclination to do good is nowhere to be found.
It is at times like these when the most efficient tool against embracing evil, abusing our bechirah chofshis, is to appeal to pragmatic considerations and ulterior motives. The Izhbitzer maintains that Yehudah was a down-to-earth “man of the world†well acquainted with hardheaded realities and that he recognized that the brothers were in the very thick of a great nisayon. There internal voices of conscience and morality had been silenced and he understood that any appeals based on morality and ethics emanating from him would be similarly ignored. And so he forwarded the מה בצע –what’s in it for us? What will we gain?; argument. Even when the yetzer hara holds sway people “remember†such practical considerations and, if compelling enough, they can dissuade would-be-sinners from doing evil or, at least, affect some damage-control and diminish the intensity of the sin.
The brothers were in the midst of a great nisayon, their collective memory loss of their yetzer tovs was so great that they were convinced that the murder that they sought to do was justified and was, in fact, the moral and ethical thing to do. Many meforshim-commentaries take the approach that the brothers convened as a Sanhedrin and ruled that Halachah demanded that Yoseph be put to death.  The Sforno (37:25) opines that they had ruled Yoseph to be a rodeiph-a “chaser†with homicidal intentions. In such cases anyone may kill the rodeiph to save the life of the would-be murder victim. While the Izhbitzer asserts that the brothers ruled that Yoseph, trying to drive a wedge between them and their father was amounted to sundering the unity of HaShem. In so doing Yoseph had committed a capital offense akin to idolatry.
A straightforward reading of the Chumash would seem to indicate that the brothers did not experience an epiphany that enabled them to see the error of their ways until many years later, when standing before the unrecognizable Yoseph, in the role of the Viceroy of Egypt, they reacted to Binyamin’s incarceration declaring … but one said to another “We deserve to be punished because of what we did to our brother [Yoseph]. We witnessed his agony when he pleaded with us but we would not listen. This is why this great calamity has befallen us.†(Bereishis 42:22). However, the Izhbitzer declares that the moment they had passed their nisayon by not actually spilling Yosephs blood that, as their yetzer haras were no longer in control, they immediately “remembered†their inner “poor-wise menâ€, i.e. their inclination to good reasserted itself and they recognized the immorality of their initial choice. They understood that Halachah did not sanction the killing of Yoseph. Persuaded by Yehudah to cease and desist they all understood at once that, had they killed Yoseph, they would not have executed a Halachically-mandated capital punishment; but a murder most foul.
The Gemara that teaches that one who praises or blesses Yehudah, the botzeia, (i.e. the one who forwarded the “What’s in it for us?†argument) infuriates HaShem is problematic. This is a particularly harsh censure. If those who praise Yehudah are so severely condemned what of Yehudah himself? The Izhbitzer offers us a deeper understanding of this Gemara predicated on the principle of the diverse tactics required to defeat the yetzer hara. Once enmeshed in the ethical challenge to reject evil and embrace good, exhortations for moral and ethical behavior, to do the right thing for its own sake, are ineffectual. As the Gemara puts it: At the time that the yetzer hara holds sway no one can even remember the yetzer tov.†It is at times such as these that the botzeia-forwarded pragmatic arguments to do well by doing good, are effective and, as such, commendable.
However pre-need, so to speak, when one is preparing for moral-ethical battles but is not yet in the throes of being severely tested, the way to wage pre-emptive and anticipatory battle against the yetzer hara is by recognizing the virtue of righteousness, the morality of goodness — not by emphasizing the ancillary benefits of, and the ulterior motives for, doing what’s right.
The Gemara that blasts those who praise Yehudah, does not condemn Yehudah himself. Yehudah understood the need for, and proper application of, the two dissimilar approaches. The Gemaras sharp condemnation is reserved only for those who think that the path of the botzeia is always the correct way to defeat the yetzer hara. There is something extremely reprehensible about one who would desist from transgressing a prohibition, when he can still remember that it is prohibited, for any reason other than the prohibition — the moral turpitude, of the sin itself. When one still has his wits about him—when he can still “remember†his yetzer tov he should resist the impending blandishments to do evil exclusively because of HaShems command.
It seems to this student that in this exegesis, the Izhbitzer is qualifying and limiting the famous teaching of our sages: “One should ‘always’ busy himself with Torah [study] and Mitzvah [performance] even if he does so for ulterior motives for the result will eventually be that, from within the ulterior motives, he will attain the level of [Torah study and Mitzvah performance] for its own sake. “ If I am reading his commentary correctly then the only time that Chazal issued a dispensation for busying oneself with Torah and Mitzvahs …for ulterior motives is once the nisayon is upon him.The “always†excludes the reflective, restful times between our actual ethical challenges (if indeed such exist). During those truce-like  intervals between those episodes when we either failed our nisyonos-tests; or prevailed by resorting to pragmatic considerations and ulterior motives, before the yetzer hara has, once again, seized control; we cannot afford the luxury of the “what’s in this sin for me? I’m better off doing the mitzvah!†sensibility. If we dare to indulge in the ethics of “what’s in it for me?†we will chalilah-Heaven forefend; be counted among those who praise Yehudah and, thereby, infuriate HaShem.
~adapted from Mei Hashiloach Vayeisheiv Dâ€H Vayomer Yehudah and Dâ€H Lechu
this is pure conjecture but perhaps the nisayon that the Izhbitzer refers to did not pass until the caravan had carried Yoseph irretrievably away but, truth be told, the actual text of the Mei HaShiloach implies that the test was over the moment that they decided not to execute capital punishment.
I do not know the answers to these cogent questions.
This article is long but worth it:
http://hevria.com/elad/baal-teshuva-world-wake/
What prevented these leaders from letting Yoseph go free on the spot? Were the other brothers unresponsive to strong leadership, or were the leaders too timid, or were Shimon and Levi the real leaders?