They believe it's true of all men. Remember, for these folks, generalizations are only bad if they negatively impact the favored group. If it negatively impacts the group they don't like, they're okay with that.
Well sometimes you have to accept that not everyone is going to understand anything and everything about everyone, and sometimes resort to generalizations and attacks.
As stated in that nuked thread
"I see feminist as quintessentially idealistic but sometimes fragile and weak in constitution
I see patriarchy as strong but sometimes immoral and ignorant of ideals.
What’s needed is something that is the best of both worlds.
As well as mutual respect and understanding by both sides for strengths and weaknesses."