TL;DR - I think the main thing is that people are trying to make this an argument about what makes "good fans" and "good teams" and that's not it at all. Forget about the A&M-TCU comparison, that was no good and derailed the thread...
The point is that MLB and pro sports and leagues are businesses. MLB wants to make money, first and foremost. They don't care if DFW fans are "better" or demand more excellence. They care about having eyes on TVs and butts in seats and people buying jerseys. If DFW isn't crushing it supporting the Rangers, then there is no chance they are going to get another team. You can rationalize or justify that lack of support however you want, but it's not there on a consistent basis and the Rangers or the Dallas Devil Rays or whoever aren't going to be contending for titles every year.
So MLB is going to give the expansion franchises to cities that don't have teams that in the long run may get the same support as the Rangers, which is middle of the pack, which is fine. But they aren't going to dilute a fan base that is already giving the franchise average support.
The point is that MLB and pro sports and leagues are businesses. MLB wants to make money, first and foremost. They don't care if DFW fans are "better" or demand more excellence. They care about having eyes on TVs and butts in seats and people buying jerseys. If DFW isn't crushing it supporting the Rangers, then there is no chance they are going to get another team. You can rationalize or justify that lack of support however you want, but it's not there on a consistent basis and the Rangers or the Dallas Devil Rays or whoever aren't going to be contending for titles every year.
So MLB is going to give the expansion franchises to cities that don't have teams that in the long run may get the same support as the Rangers, which is middle of the pack, which is fine. But they aren't going to dilute a fan base that is already giving the franchise average support.