The problem with watching fighting games more sedate than Marvel is that it's not hype if you don't know what's going on.
There are PLENTY of people who think SFIV is boring to watch, and quite a few of them (I'm not saying ALL of them) betray that they don't actually know what's happening, so don't know why a skillful or tight fight is meaningful.
But SFIV is still close to 1 on 1 SF2 so it's familiar to a lot of people. It's easy for many to get hype about watching an SFIV match between good players.
Plus, SFIV was the "revival" game for Capcom, so we all probably watched it intently and figured out what was going on pretty fast.
Personally, I am getting more hype while watching SFxT the more I figure the game out and see why it's not SFIV. But like most games it's going to be boring if you don't have anything to look for in one of its matches. It can't help that the meta game's development seems to have been slowed down by bitching about the timer, people playing it like SFIV, not using gems, and not taking advantage of openings the way they probably should be.
I suspect this is another reason why some folks are unhappy with Evo being 2 on 2 only... it could have been a major turning point for the game if people arrived and really stepped it up. So we could see how it played "normally" i.e. with one player on each side as opposed to teams.