Because it focuses on the single game, yes. Some people may just want to discuss the specific game, just as people would rather discuss Mass Effect 2, Mass Effect 3 and the series as a whole seperately. When someone does a search for "Sonic Generations", they weren't getting any topic.
WHAT IS THIS ALIEN?!?
Seriously, this just blew my mind. As I was watching it, I was kinda like "Cool, but nothing too interesting yet." and then old school Sonic came along and I was like "HOLY CRAP IN A BOX!!". Definitely eager to see how this will turn out.
If I could buy Brawl even though I thought I was never gonna get a Wii cuz I had a 360, I think those of you who really want it will get even if you don't have a PS 360. Just a suggestion, you might regret not doing it.