Ah, the good ol' fanfiction- real writing or writing down your sexual fantasies for thousands of people issue. Personally, I prefer fanfiction as a writing exercise,because I think seeing it as writing gives more of a push to improve. I mean, no one that I know of tries to improve their masturbation fantasies, but many want to become better writers. Being able to say "hey, why is mr tough guy in canon acting like a twee little girl" or "uh..why are these dudes walking hand in hand in 19th century england?" makes for way better writing than 'eh, that's your kink'.
The thing is that sure, some readers are reading for kink and kink only, but many readers would like a good story that is consistent and that isn't constantly throwing them out of the story with "is that physically possible?" or thinking "yeah right" about the character's behavior.
Personally, I rate kink as the same as self insert. Yes, you're proud of your wolf of the zodiac story or your story about guys having sex standing on their heads. It makes you hard, wet, or whatever else. But don't be surprised when someone says "But there's no wolf in the zodiac" or "man, that sounds like it hurts."
And don't be afraid to inject some realism into your sex. It's often hotter when you go back to reality because then you can pull things that may have gone unnoticed by the last thousand fic writers. Research and thought gives you new views and keeps your work fresh.
