I don't even people like playing canon characters if their writing a roleplay or fan fic based on a fandom (because 90% of the time, they get the character horribly wrong and impose their own ideas on said character instead of embracing how the creator intended them to be), so playing real people, who are endlessly complicated and multifaceted that can't be easily shoved into a trope, is kind of tasteless in a few ways, especially because whatever problems you have writing fanfics about a fictional character, you aren't going to truly understand a real person.

Plus, as Kaga said, it's goddamn weird. Imagine stumbling across a story somebody wrote about you. It would feel wrong.