Roleplays used to be be a problem in fan fiction. There would be an excessive amount of them, which would push down all the stories to the second page. Roleplays are posted on more often and tend to be at the top which wasn't very fair when there were so many. Since fan fiction is meant mainly for stories, this caused a lot of problems and when there were already many roleplays on fan fiction the writers would get annoyed at the new roleplay threads. It's not much of an issue anymore though.