I’ve probably talked about how much this concept annoys me. The greater reason that it annoys me is that it is almost always a method employed by in-universe writers on television and in film.
Richard Castle can’t write anything without basing it on something that actually happened, apparently. (also can’t write more than one book every four years…) What’s-his-face from Alex and Emma had nearly lethal writing block because he had to take a summer of his life and paint it into a different historical period.
I’ve known so many female Alexes that I can’t remember which of them is Kate Hudson. Seriously, I have met maybe one male Alex for every three female Alexes. But I digress. Awfully.
A real version of this concept that I think you see more often is something akin to a crossover. Generally with celebrities. Mr T and Jane Austen fight gangland violence! If it’s ridiculous enough, most anyone will express a desire to see/read it.
The thing about any of this is that perception is not a finite thing. It’s like when somebody asks an artist to draw a portrait. I have a great deal of respect for portrait artists, because I’m a cartoonist. I dread being asked to draw people. I would never ever want to write someone into a novel.
Comedy or parody make all of this pretty easy, but when it comes to request or anything even remotely serious… Or that has expectations… Ugh.
The person being made into a character has an idea of himself that could be diametrically opposed to that of his friend the writer. And say that they have three mutual friends, at least one of whom knows the first guy better than the writer.
The result generally ranges from vague disappointment to hurt feelings.