Just because you've lost interest doesn't mean other people shouldn't be able to enjoy your contributions.

^

The contributions within a club are for that club and the members who are fans of it. They don't belong to the person who added them originally.

^That's true but what about original stuff like original articles, forums and images that belong to the person like original fan art, perhaps?

If you want all traces of you wiped that bad, you can delete most of it yourself. But what if you decide one day that you want to come back? All that stuff might've earned you a medal by then.

^Good point and there is that possibility you'll want to come back and if you do get a medal, you might as well stay. I mean it's hard getting a medal from fanpop these days. lol!

I don't think it's that necessary.

No, because I would be screwed

The others who are still members of the club can still enjoy the content. Just because you've lost interest or even decided that you now dislike the subject doesn't mean that those others deserve to lose the stuff.