TF2 was a fun arcade FPS with good artistic design and a sense of humor that came out when every other FPS was a gritty war simulator or a Counterstrike clone. People who were tired of BOOM HEADSHOT and gray buildings bought TF2 and had fun with it. I haven't played the game in a while, but I don't really mind the stupid community that built up around it because stupid communities are preferrable to the kind of smug elitism that surrounds more hardcore games.
I avoid both. TF2 was a fun game that had nothing to do with teamwork the second they added achievements, and went down from there the more bullshit they added.
These days it's basically 4chan; the game thanks equally to its devs and community.