Is your issue the fact he's anti-social, unpopular and embraces it? I mean there's character development but his character for the longest time is how he acknowledges that often the simplest solution is one that isn't popular. It's a nice change of pace from most of these shows having people who go WAY the fuck out of their way to help others, this guy likes the simple straightforward solution no one wants to think about. The Batman jokes are there for a reason. Keep watching as the interesting aspect of his character involves his world view and personality greatlyhurting those that grow to like him.
That's actually what I kinda don't like in the series. Not his world view or how he interacts with problems, nor even that people don't like his seemingly self-destructive attitude towards problem solving, but rather just how quick everyone is to literally and viciously hate him just because he handles a situation his way. They do this, oddly enough, at time while still knowing and enabling that kind of behavior.
Its why I hated the intra-club dynamic in season 2, immediately he says he'll fix a problem in the last second, everyone acknowledges him to do it knowing full well he will get hurt in the process, and yet everyone gets pissed and gives him the silent treatment for it. Its bullshit.
Hachiman's attitude and use of problem solving aren't good, sure, and he does eventually learn (somewhat) that he shouldn't take his relationships lightly, but I'll be damned if everyone he is friends with (or at least inside the club) isn't a horrible asshole.