Twitter is a culture, and bringing money into the culture of favoriting and retweeting could change it, possibly for the worse. Twitter has a right to stop that. I'm not saying their intentions are necessarily so pure (probably not), but it's also not out of the question.
It's also not out of the question that I'm just a brain in a jar and all of you are an illusion. So maybe let's first talk about likely things, and then about the infinite amount of things that cannot be disproven... ?
I think it's different. As I understand it, with favstar you can't actually give someone money. You can give them a trophy (or other virtual rewards) which you yourself buy with money. The key difference is that the system is still fundamentally about nothing more than status. You make content and receive thanks and status VS you make content and get paid for it. Innovations to the former system are far less likely to cause a big cultural shift than a switch to the latter system is.
