SF has gone through a number of evolutions over the years, and has become far more mainstream. As someone who's followed SF since '02 or so, it's barely even the same site. I suggest that the older posters are leaving because the new SF isn't to their liking.    However,  for the cause  the new SF is a far superior site to the old one. I'll take a strong SF with a wide-spread message over one with few members, most of them unable to communicate effectively with anyone outside of WN circles. Anyone who's upset about the new, mainstream nature of SF has probably found themselves moving to sites where the topics are much like the ones I used to  laugh at  5-6 years ago. I wasn't an anti by any stretch, but the old ('02 or so) SF's population contained a LOT of jingoistic because we're white we'll prevail even without planning type people who were really only good for laughs. On the other hand, with the '09 vintage SF, I don't have to grit my teeth before showing it to prospective WN's.