Why are feminists angry?

Philosophers believe the pendulum must swing both directions for a time before finding it's equilibrium.
In short, we need someone to be angry about injustices to counterbalance the inappropriate actions, which unfortunately come at high personal costs to an individual for the sake of the cause.

Why some people are mostly normal, then go batshit crazy

It's incredibly taxing to be fighting demons day in day out and sometimes you need a rest by letting them win.