I have once again been broken by the doomer mentality that is japanese teenage manga and am forced to come out of my passive consumption mode to comment as a rant.
When you're as deeply ashamed of your own hobbies and interests as Stowie is, it becomes really difficult to talk to people because you feel like you can't let them know anything about you. This insecurity and shame also makes it really difficult to deal with the banter and sparring that's such an important part of communication. So, you end up putting up walls around yourself, and people end up ignoring you. There are also, of course, cases where people do end up getting bullied for having nerdy hobbies, which complicates things.
By the way, if we're relating our own middle school experiences, in 9th grade a classmate asked me "do you even know how to say things that aren't sarcastic jokes?" and after I stood there for several seconds, confused, stunlocked and dumbfounded he just laughed and went "see, you can't!"