... So? Fanfiction and fanworks in general are sometimes completely awesome and should be supported. I refer to Touhou and frankly ANYTHING RELATED TO IT as justification for why fanmade works are awesome.
But even if we're just talking about Fanfiction alone, there are some well-written works. Granted, Fanfiction.net seems made to directly appeal to the idiots that love gay fanfiction pairings, stupid self-insertion stuff, and whatnot and whatnot, but I've seen some great works of literature in fanfiction form, and sometimes some of these things are just plain fun. I've seen some nice crossover work in fanfiction form, and to go back to fanmade work, I would like to refer to Haloid and Dead Fantasy for how to make an awesome crossover.
And, as a bit of a fanfiction writer myself, I take offense to the generalization that we all obsess over self-insertion or gay pairings. Some of us have a brain, thank you very much.