About one person quitting? Very likely (although I'd care if certain posters quit; they're fun. You're one of them -- I must admit I didn't notice you quitting).
About why posting politics is so enticing? I think a lot of people are interested in that. Every forum I've ever seen (even college hockey forums -- what could be less political on the face of it?) have political threads and they're all the same -- same perspectives, same mix of invective, preaching, holier-than-thou, honest discussion, hair pulling, leg pulling (all of which have been displayed here in 15 posts) -- but above all people getting the same fix. So why are certain people wired into that and what's different about people who simply skip over it all like an episode of Twilight?
Take away the accident of a given poster here or there, and what's left is something unusually compelling in an ocean of emotional disengagement. What makes this interesting enough to develop sincere likes and dislikes? Or to put it in a way you might like more, given that plenty of us are attention whores, what makes one stage more or less attractive? You would think that most of the action would be packed into topics relating directly to the forum subject -- that's where the highest hit rates should be. That would indicate that it isn't purely attention whoring (as much of that as there is), but that there's something in the subject itself that is catnip.