To follow on rzombie's coment, Grimmas, you're a big lucha fan. Do you watch lucha blind to a given performer's mask?
Certain fighters in UFC have undoubtedly gotten opportunities based upon their look and personality/charisma. But I don't think anyone there would lose an opportunity because of their look. Regardless of the promotional machinations that may drive shows, at the end of the day it is a sport and thus very different professional wrestling. If a given fighter goes on a run of wins like Jon Jones did en route to his first title challenge, that fighter is getting a title shot regardless of their look. Many fighters are pretty cut and fit because of their training, dieting and other measures they take to make a certain weight. This is less so the case at heavyweight, where not everyone exactly looks the part of a Brock Lesnar or Overeem. That's what happens when contests are not predetermined -- you do not get to choose which package or presentation comes out on top.