So what I've gathered is, nobody likes Joel anymore. This is kind of a problem, since he's supposed to be the main character.
People's main issues are that Joel is dismissive of other people's interests, is inconsiderate of his family's opinions, has some smart-ass comment to say about everything, acts without thinking, swears too much, and has no real problems that are worth complaining about - he's not in a bad enough position to be as bitter and sarcastic as I've made him, and he comes off as just a whiny petulant jerk. I'm not going to lie: this is a genuine surprise to me. I thought I'd well and truly established that Joel's creative ambitions are unappreciated at home and at school, and that he uses sarcastic humor as a coping mechanism for being emotionally beaten down all the time. People's reaction to that basically amounted to "Yeah, we get that, but he's still an asshole."
I think maybe the problem is me. I'm just not a talented enough writer to get my ideas across clearly. What I really need is contribution from other creative minds, people who can take my ideas and help me build them up into something that an audience will want to read. Anybody who has any suggestions for how to make Joel more likeable and sympathetic and maintain the theme of rebellion against oppressive forces, I am sincerely open to hearing them.