You know what I do with topics I'm not interested in? I don't read them. Life's too short to be worried about how other people have fun.
I'll fully agree that Drafts have a signal to noise issue, that much of the discussion amounts to "good pick!/bad pick!", and it renders the rest of the Drafts & Lists category unusable during the period of a draft. (That said, other than the End of the Year lists, this category averages something like 3 or 4 non-draft topics a month for the rest of the year, so it's hardly busy.) And, some of the participants don't offer a whole lot. I think it should be mandatory to post just Why you picked what you did.
I'd count the plusses as:
1. It's a game. It's fun.
2. It often calls my attention to obscure movies which go right into my Netflix queue.
3. The genre drafts inevitably have at least some discussion about what defines a genre.
4. It's a game. It's fun.
5. I enjoy the social aspects. You do learn more about your fellow posters, their tastes, and idiosynchrocies.
6. Discussion of the merits of some films inevitably breaks out. Discussions that will involve movies other than Watchmen, Wolverine, Star Trek, Observe & Report, and Terminator, which seem to have absorbed much of the attention so far this year.
7. The discussions that do spin out tend to have multiple points of view, since people are approaching the draft with different strategies beyond good/bad.
8. Hopefully activity in one area of the board will spur activity in others. If I'm on the board, I'm certainly not reading just the draft threads.
9. It's a game. It's fun.