Maybe it's because you've been in fandom long enough that you don't run into it any more?

I know I definitely got hopped on in a few quarters when I posted by DarkXander fic-a-thon entry that I had a Xander/Faith/Spike ship with a definite bi-Xander that wasn't even that explicit. *shrug* A few people commented on that post they get slammed quite a bit on their slash.