From a marketing perspective, it is harder to build and maintain interest in a sport that's individually based than one that's team based. If you build fan interest around teams you don't have to worry about things like career longevity and injuries. The 49ers and the Cowboys will still be competing in the NFL in 50 years whereas GSP and Anderson Silva will be long gone from the UFC. Individual personalities within the team sports are still important, but that is partly mitigated by the numerous other athletes competing simultaneously and the fan interest in the team, regardless of it's members. But the team concept in MMA is lame.
"I've never been happy with my fights. To not finish is even more upsetting. I hate it more than the fans hate decisions. It's not the point of fighting. You're there to finish the fight." - Jon Fitch