I think it may be the thing about them still being about, to know about it and possibly to read it. But the more I think about that, the more I think they'd probably prefer to read/know about decent RPF/S than some of the purportedly non-fictional stuff that gets written about them.... I think it's when I got to that realisation that I started not minding RPF. It still feels a little 'wrong', but once I get into a story it's just a story, iyswim.