The entire question for many men is whether the situation worsens itself if they do a certain thing, most are held back by something like a family or a job they like which builds up inhibition, furthermore, some of them are treated very well so there is most of the time no reason for feelings of hatred/embitterment to develop in the first place (prevention).
But with men that have been ostracized/have nothing to lose - what can you really do? Threaten them with social exlusion? - Laughable, their status doesn't change, they were excluded to begin with and sometimes even hated, if you are treated like the devil you are on principle free to act like him on a rational cost/benefit perspective because there would be nothing but subjective morals in your way. And some day the cost-benefit-analysis just shows them that the benefits outweigh the costs by far, so they act.
The question that asks itself is after (a certain time/after certain life experiences) not "Why?" (because conventional morals were long replaced by subjective morals), but "Why not?", bullying/exclusion/suffering doesn't make humans better per se, it can lead them to value what little they have and defend it with fierce force/no concern for others while envying those that are better off, suffering shows you ultimately that in your worst hours you are on your own, so a certain egocentrism/self reliance/lack of care for others/etc. afterwards can be expected (of course not in 100%). And in a criminological perspective you see aforementioned ideas always.
Not condoning anything done, but the logic behind it is for anyone understandable. If you don't want people to do shit to you, don't give them a reason to begin with. You cannot exclude many males from a normal life and expect them to just accept it/die off.
