Perhaps I've spent too much time reading around the Diablo 3 forums (although "too much" is very little time there), but it seems the game's biggest fans are the people whining and bitching about it most. Diablo seems to have the same thing going against it that WoW does; people don't play it, stop feeling satisfied, and look back on a good gaming experience. They play and play and play until they hate it.
I'm writing out of my ass here, so this may seem a bit unfocused, but my big issue is not the whiny, under-appreciative community, but rather the issues they're whining about. 98% of posts and conversations I've had with burnt out, ranting ex-players complain about Inferno mode being unfairly difficult.
You've already beaten the game three times with just that character. Isn't it about time the game got its revenge?
I think the difficulty wall of hitting Inferno mode (more-so act 2 than 1) is brilliant. It encourages the players to rethink not only how they're playing that specific character, but the whole game. It's an unfairly difficult goal to achieve so you have something huge to strive for. On the other hand, if you don't enjoy this type of tough love, Inferno mode should be pushing you to try expanding what the game is about. Try out a new class! You still have three difficulties of fun with four more unique classes! Try Hardcore mode where the game is still easy, but far more intense with what's on the line! Go achievement hunting. There's some really fun ones (and some frustrating ones). If you have any buddies that haven't played yet, get them into it and play some non-public co-op. If it's Act 2 you're stuck on, play Act 1 again!
My point here is that people complaining about Inferno act like it's the only thing to do in the game. I think their frustration should be encouraging them to try a different aspect of what the game has to offer.