I can't remember where I read it, but there was an article that showed TCU games against quality opponents on TV do in fact generate big viewing audiences in the DFW market. The Big XII already had the DFW audience, but now it has more.
There is also a growing alum base in California, so the Big XII will have more TVs in that market now too. So, to say TCU adds nothing is inaccurate. It may not add much more, but it adds something.
I'm excited to see how it all plays out.