I think it's not exactly fair to blame him for disliking RPF. It's not everyone's cup of tea, and since he knows some of the guys personally the more explicit fics (if that's what he's seen) might have weirded him out. I know one of my classmates used to write RPF back in school, and it was quite distressing to find out that a stranger was creating stories about people I knew. I'm not saying that's a good comparison, but I think that he might see it that way from his perspective.