In chatting with one of my friends, who's very big into this sort of music, she had some thoughts I hadn't even considered.
I figured, Kanye, who had been seen drinking and is pretty opinionated to start with, probably would have waited to see if Beyonce won anything before acting had not been drunk.
My friend pointed out that the list of winners was probably already leaked; after all, you have to let the artists do some prep. So, he probably knew Beyonce had an award coming. It had nothing to do with Taylor and Beyonce.
Taylor Swift just happened to be his first opportunity to grab the mic from someone who wouldn't respond by giving him a thorough beat down. Essentially, he was doing what he'd like to to Eminem, but didn't have the guts.
By picking on Swift, who's hardly more than a kid, really, he made a really bad move. Everybody hates it when a bully takes candy from a baby.
I've never cared for the genre of music personally, so I don't really know much about Kanye. The more I learn about this guy, the less I like him. I'd be shocked if people didn't start boycotting his stuff over this tantrum.
He should be barred from awards shows. They won't do that, of course--knowing he's so unpredictable could bring them some ratings.