I've never hated a person because of the console they prefer, but I can't say I'm a fan of Nintendo.
It's not so much the games, as it is the lack of games and the over-all childish mentality of the whole system. I don't mean that gore-wise, but play wise. The way they handle playing games over the internet and such...
They lack in graphics and power, they lack in DLC, and a good chunk of their games can't even be played online. I was crushed after finding out I couldn't play Toejam and Earl with a friend over the internet. No online contra? No online Bases Loaded? BOOOOOO!!!!
I really liked the new side-scrolling Mario game, but I can't help but think about how much better it could have been if Microsoft owned Mario. We'd get DLC for new maps and new worlds... but not with Nintendo.
Nintendo doesn't get very many 3rd party games, and when it does they have to be dumbed down. You don't get Dead Space, you get Dead-Space the on-rails shooter. Which is probably a good game in it's own sense... but I like having the ability to play the original retail game.
The system is just too under-powered. You'll never be able to play a game like GTAIV on the wii... you get very little adult oriented games, crummy online capabilities, and a lack of game choices due to poor hardware when you side with Nintendo... so why do it?
I don't know... that's just me I guess.