I actually think in some ways the so called fanboys are just more honest (whether that comes from maturity or immaturity is case by case I'm sure). What it comes down too the vast majority of time is attachment, affinity, obsession and what have you. I'm a believer in reasoned argument, but most of what takes place on the comic boards is the illusion of argument. I can break this down some if any one wants to challenge the notion, but whenever I read a long multi-page argument about how the Hulk should beat Superman, usually the arguments are so bad or baseless (and usually because the premises are ad hoc and essentially arbitrary), that person might as well have said, "Hulk beats Superman because I like him better, and the thought of Superman beating the Hulk makes me very uncomfortable. This is very likely because at a young, vulnerable, and delicate age I began to associate the Hulk with warm, safe feelings." I honestly think that emotionally speaking, for many comics fans, the idea of another character beating up their favorite superhero mascot, is like imagining a stranger beating up their childhood teddy bear. There are moments where reason is more or less operative in decision making, I don't think the battle board is exactly replete with those moments. It's a bunch of highly emotionally charged language, masking itself as disinterested intellectual back-and-forth.
Also, I find it highly unlikely that Thor fans are any worse than Superman or Hulk fans, or Nightcrawler fans for that matter. I believe it's the same psychological make up. The particular object avatar is more or less interchangeable.
---the late great Donald Blake
"I think Wolverine would win because I like him." I forget who the opponent was, though I think it was either the Hulk or Superman. After all this time, I forget who the poster was, too. But I replied something along the lines of: "This is the best and most honest reasoning I've seen. I'm not going to argue with you on this."
So, in other words, I do think you're onto something here.