dont know how common is it, but some grow up out of it. The reason why they have those beliefs is how they feel, the info they show is just a tool to self affirm their beliefs. We all do this at some point of life, is mostly a childish mindset. The problem is that they dont face reality by themselves, just stick to the computer discusing this topics with more bitter and childish men. Some will never grow out of it. In my opinion, they just need objective facts, more personal experiences and a supportive AND
"i wont take your bullshit" women figure, like their mom, partner, boss, friend or whatever. And cut their internet conection, for a year or two.