Peterson relates it to feminine nurturing and maternal instinct (which men also possess to a degree, the impulse to protect a child) being improperly applied in situations where it does not apply, namely to adults rather than children. This is an important point. But I think it runs deeper than this too.
Critical theory and deconstruction philosophy came from Marxism and merged with the Left--- why? Marx codified the moral madness of turning child-psyche into psyche as such, seeing the world in terms of groups of black and white "good or bad" rather than seeing a world full of individuals who somewhat occupy various different groups but are never defined by that partial group membership. Marx collapsed the structure of the self to its external relations. The Left seized on this as a way of attacking existing power structures. This is effectively the same as the Left saying to oppressive power, "you're oppressive and irrational, therefore I will not exist!" Yes a lot of the traditional targets of leftist philosophy are legitimately irrational and oppressive, but 1) the Left's response is also irrational and oppressive, and 2) their response fails to differentiate between kinds and degrees of existing powers. Some power is obviously more benign than others, some power is more rational or necessary than others. The way to attack a necessary irrationality is not to attack the necessity but to attack the irrationality in specific, therebt improving things.
Marxist derivations gave up on that in order to tear down the entire world. That effort is called communism.
Why did the subjectivity structure collapse in these sort of people? I think Marxism preempts their subjectively development before it gets going. Gives an excuse to close your eyes to the world rather than deal with it, which would be much more difficult. SJWs cannot assert themselves as individuals against anything, and they compensate for this deficit by going full-crazy mode on anyone they perceive as an enemy. Their self-valuing has been reversed: they value-self (import values from outside) because they cannot push out values from themselves, because they do not have a self. And when you merely import values, it becomes like eating: you only eat what is actually food and what tastes good to you, you 'violently' reject eating things that aren't actually edible. The SJW defines as inedible anything that would challenge their own anti-self-valuing methodology. They reject thinking ideas like we reject eating poison.
Marxist ideology teaches non-self-valuing, "value-importing" and thereby turns human beings into passive unthinking beasts ravenous for the next meal.
1) Marx taught the subjectivity-collapse as method (Luther's idea)
2) the Left adopted this method for political power
3) philosophy tried to rationally articulate and justify this, because it didn't want to align itself to "the right"
4) group think took over the Left and turned it from rational revolutionary impulse against real irrational oppression, into mere passive liberalism (censorship, virtue signaling, religious moralism)
5) a new ideology emerged, the modern liberal Left, "progressivism"
6) philosophy again tried to enunciate and justify this, which led to academia becoming infected to its core with progressivism
7) academia teaches kids to be safe spacers