Gabriel: "Because of the sale of Joseph. Every day the measure of justice has been speaking in accusation before the throne of glory, saying, 'Did You write in vain a single letter in the Torah?' You said, 'He that stealeth a man, and selleth him . . . shall surely be put to death' [Exod. 21:16]. Yet the ten tribe fathers sold Joseph, and until now You did not requite them or their progeny. Therefore a decree was issued against ten sages of Israel." R. Ishmael: "Has the Holy One been unable to find anyone but us to requite until now?" Gabriel: "As you live, Ishmael, my son, since the day the tribe fathers sold Joseph, the Holy One has not found in any generation men as righteous and pious as the tribe fathers, save only you. Hence He will requite through you."
I found this disturbing. It goes back to the punishing of the children for the sins of the parents. A theological position which was reversed in the prophets. This is a particularly nasty example. First, it is much more than the 3rd and 4th generations as stated in the 10 commandments. Second, those punished are the best of the best. Why does it matter who is executed? How many were descendants of Joseph or Benjamin?
R. Simeon ben Gamaliel and R. Ishmael the High Priest were seized to be executed. R. Simeon burst into tears. R. Ishmael said to him, "Avrekh you are but two steps away from being put in the bosom of the righteous, yet you weep!" R. Simeon: "My heart fails me, because I do not know why I am to be killed." R. Ishmael: "In your lifetime, did a man ever come to you for judgment or with a question, and you kept him waiting while you drank your cup or tied your sandal or donned your cloak, even though the Torah says, 'If thou delayest at all' [Exod. 22:22] whether the delay be long or short?" At that, R. Ishmael said, "You have comforted me, my master."
Even R. Ishmael doesn't accept that reason, he has to be given a different reason.
The death penalty is a penalty for humans to implement, G!d has his own mode of punishment, caret.
Finally, it shows a G!d who is completely controlled by justice with no mercy allowed.
The need to explain theodicy has always been a problem, but I found this one especially bothersome since it makes G!d look very bad. She is controlled by Samael and forced to kill His greatest disciples.
This introduction trivializes the martyrdom stories it leads into. Rather than suffering because they love G!d and try to do Her will, they suffer for no good reason.