The TV quiz participants cartel!! It's been going on for years.
Yes - It does happen - remember we saw one of The Catcher's last week.
I worked with a guy a few years ago who was pretty good but could not get a major TV appearance for love or money as he did not fit the profile as an interesting contestant. He did do a couple of late night minor shows but not any of the biggies.
He explained it to me and told me to watch out for the regulars on the mainstream quiz shows and he was right. Teams are often put together by the TV Company making the show which is why somebody may appear like above (not UC by the way). And now because we have more quizzes being shown on TV as they are cheap to make, people seem to be noticing.
It seemed the only show you could get on without having to fit the profile was 15 to 1, but then the contestants were not really chatted to like they do on other quizzes.