And is having the same group of people in the media a bad thing? People like rivalries, people like simplicity, people like familiarity. When a new face makes the TV show, some of the more casual fans will not respond well -- "who is that? I don't care about him!" and they'll turn off the TV or change the channel.
There's 43 guys in every NASCAR race, but nobody cares about the guys who aren't consistent frontrunners. There's over a dozen players on an NBA team, but nobody cares about the benchwarmer who plays garbage time if he's lucky. People want to see the big names, they want to see the stars.