She teaches little girls that women can be strong and independent and that scares the shit out of weak men.

Misogyny. Barbie is about feminism. Feminism is about women having power and not being objects for men to control. Men hate this. Republicans support this oppression entirely.

They’re secretly gay and are afraid that seeing feminine concepts and objects will make them slip up and do something fabulous, so they put their emotions in a box and CRUSH IT

To be fair, it’s only a very particular subset of grown men. For instance, I am a grown man, and I have no problem with Barbie stuff. In fact, I’m gonna go see the movie next week because I’ve heard it’s incredibly good. Weird reactions to stuff like this seems to always come from men who are members of hyperconservative and often theologically-oriented groups.

Republicans and stereotypical incel neckbeards hate that the male sex no longer rules supreme or controls every aspect of the Internet, and modern Barbie reminds them of that fact

Aside from the typical misogyny this movie in particular makes some pointed criticisms of masculinity. They either don't see that reactions like this makes their masculinity look very insecure, or they are aware that hatred sells to their audience better than fair level-headed reactions.

Basically, they’re angry because they’re turned on.

This is similar to Hasidic Jews or ultra conservative Muslim men freaking out at western women and blaming women for being unable to control themselves.

They also can’t stand to see women who are … you know… successful at anything other than being a housewife.