I also hate the crowds and am not the kind of guy who will walk into a bar by myself and start talking people up, or necessarily will enjoy being talked up - especially if they start in on something I hate, like sports. I call myself a misanthrope, but am more a combination of introverted, shy, and grumpy. I don't mind talking with people IRL for short periods and if it's something that I'm interested in, or even ambivalent about, will do so happily. The longer the interaction goes though, the grumpier I get. I'm really good at short encounters and people who encounter me that way always say what a friendly guy I am. The longer I have to endure people in one sitting though, the more prone people will be to say that I'm cranky and not friendly.
I just hate IRL encounters with people that won't shut up. It's too much like work. I like Internet conversations because at APS for example, I can jump into a conversation when I feel like it, whether a minute after the topic posts or a day later. I don't feel like I have to be "on" all the time.