I'm not a fan of anime, livejournals or milky drinks, but then I'm not a fan of anything. I have problems with the whole concept of fandom, or 'fanaticism' as it used to be called. One common thread I've noticed in a lot of fan communities - both online and off - is a lack of anything approaching critical thought. A lack of criticism towards the object of fandom, and a lack of criticism towards the state of being a fan. All I see is blind idolatry, and blind dismissal of anything perceived as a threat or a rival. Sure, you often get fans who dare to break away from the pack, who dislike their idol's latest work, or even start to turn against him; but such disillusionment is part of the inevitable trajectory of the cultist. The same can be observed in adherents of Scientology, or any of the Christian sects. Lapsed fans will often take up another cause with the same unquestioning fanaticism.
Everything should be criticised, including the things you like, especially the things you like.