Couldn't agree more with robb2140, he hit the nail on the head, I'll just add a little more to what he said.
Riggs losses came from some of the top talent in the UFC. I mean Diego, Swick, and Hughes thats a pretty tall order. But the UFC doesn't let you lose to many before you are gone, thats what makes it intresting. It's either win, or get out. I think we will surely see Riggs again, and a belt is not out of the question for him. He needs to not drop so much weight, that has to slow him down among other things.