I know this isn't going to change your stance about it and I'm not trying to, but not every RPF is a kind of "replacement" for characters. In fact, I think most isn't. If I'm into figure skating and shipping two skaters, no amount of writing about Legolas and Aragorn or even about those two skaters in the anime that was so popular a while ago is going to scratch that itch.

I just find the anti-RPF thing incredibly weird because it seems to be such a normal thing. When I grew up, there were columns in teen magazines where people wrote out their fantasies about meeting and falling in love with celebs. No one batted an eye. People write books and movies about fictionalized versions of celebrities (who usually don't get a say in it). Fandom is the only place I know where people make a fuss about it.