Texas situation is so weird. They didn't need the money for them it was a perception problem that the big12 was a weak or lesser conference which part of the reason for that perception was the fact that texas has been very bad. You could argue that they left for stability reasons but they were a huge cause of the instability so who knows with them.
Texas has destroyed every conference it has been a part of. Give it a few decades - they'll destabilize the SEC as well when they realize they're not as loved as Alabama... or Georgia... or LSU... or Florida... or Auburn...