Left wing scenes are socially coded against "dorks,"
Ironically enough, I notice this in online spaces more than real life ones. You've got TrueAnon's "be normal," its subreddit embracing ableist slurs, that whole Cum Town segment making fun of someone for saying virgin shaming is bad, people on this very site saying "bring back bullying," etc.
Meanwhile, the IRL leftist organizing spaces I've been in have been full of unabashed nerds and very good about not tolerating ableism.