Perhaps not a mob, but everyone's 'What If...' theory is different. One person's logic isn't always what another's is, and while I can't see some pairings, I'm sure others could. What I've always liked, especially with HP, is that there's very few pairings that could be written and the fandom be revolted on the whole. It seems to be more of a 'can you write' versus 'what you write'.