Simple: Santino and Carlito were a comedy team while Rhodes and Holly, while boring, were a serious team. This is the same issue that people had with Santino as IC Champion the second time around. Having guys like that with titles makes the belts look silly. With a team like Rikishi and Rico, the epitome of a silly team, Rikishi was a somewhat dominant force and Rico wasn't bad at all. With Santino and Carlito, there were a few issues. First of all, the Santino character isn't a good wrestler. he's a comedy act and is never on TV in anything other than bad comedy skits anymore, and I include his matches lately in that grouping. Carlito was about as close to being fired as you can be while not actually being fired. They were a team for all of a month or so as you said, which is the other issue. Just because two guys are thrown together like that and get a cheap win, that doesn't mean they belong in the title picture. In any sport if a weak team beats a powerhouse, that doesn't immediately mean they're better. The tag division is in such a mess today that havign another comedy team would have hurt it even more, and since then Vince seems as if he's at least trying to fix it a bit. Carlito and Santino would have held them a short time and made them look even worse.