Even as I typed it, it didn't seem to fit together as well as when I thought about it. Perhaps I should say the bottom line is there's a correlation, but not necessarily a causation.
I've known these people, I've hung out with these people, and they themselves told me their mental problems. Aside from Chibi and the girl at the kennel, I've had close-up views of their lives. Some is tragic, some is their own damn fault, and some were herded into how they act now. Both with me and others at the kennel, she'll occasionally ramble on about her favorite shows, though she didn't say anything about manga.
Ew, I made myself sound like a bigot. I apologize for that and take responsibility, I just needed to vent a little. I really try my best to be tolerant of others, and I don't have much against anime as a hobby, or other denominations I have mentioned so much as I just can't stand when people take it to extremes, and then bother others about it who don't necessarily want to hear it.
I'll take three other examples to try to make up for it. Say someone is interested in MTG/DF/Baseball, just as examples. It's alright to me to mention it if I don't like it, and I'll probably say that I'm not interested in the example, but it will bug me to hell to have someone ramble on about how their deck is superior to their friends, that their fort is doing ___ (to someone who wouldn't know what they're being told anyway), or how their sports teams are vastly better then the local rivals. Perhaps the blatancy/obsession part gets to me?