...and I'm probably the user you've seen being somewhat anti-real person fanfiction from a personal perspective. I used to write it. I think I had 12 or 13 stories at one point. Internet being the internet, they're still out there somewhere. I did a couple since then that my muse made me write and those you won't find. They're at the bottom of a well, guarded by a girl with long black hair. Initially I stopped because of various lawsuits and criminal prosecutions against writers of real person stories in various worldwide jurisdictions that made me feel it was not worth the hassle, later I stayed stopped because of things like this, and this, and similarly, with Twitter and the rest of social media it is ridiculously easy for those fics now to be sent to the subject of the story in question by trolls. general nutjobs or anybody with access to Sony's email server. Hell, Jimmy Kimmel has the subjects of rude tweets read them out, and you can go on youtube and see other hosts get the likes of Daniel Radcliffe to read slash. So that's another reason, I just don't like to think how celebrities would feel if they read something I'd written. Especially as many of my stories were at the, uh, less romantic end of the spectrum. Still, other folks have fun writing and reading them and I don't have any problems with that so it's fair to say my opinion is fairly self centred. For me, it's definitely the real person being involved that stops me. Take them out and I'm pretty fine with most content. I'll avoid things with characters below 16 in sexual situations but beyond that I'll try most things. I've even re-written one or two of my old celeb stories into non-celeb stories to re-use the better descriptive passages (that's relatively speaking, of course, better for me is still trash!).
Any fantasy that needs to be shared feels, to me, like it can be written with a fictional character, even an "OC" with strong similarities to a famous person. Apart from a RPF gaining additional readers from fans of a specific celebrity, which writing hobbyists always enjoy, there don't seem to be other benefits except, well, folks enjoy writing real person fiction. I did. And that's why, although for my own personal reasons I've stopped I don't hold anything against folks who do still write them or share them, or have them tattooed across their back so that Nathan Lane can read them in that long fantasised chance encounter in Broadway men's room.
Look! A RPF ref! Aren't I the most awful hypocrite!
Anyway, good luck with your celeb fics and I wish you all the best.