Having wealthy alum, and having wealthy alum that donate are different.
The State of TX has always had a culture built around this going back to the SWC days. Those big money execs want bragging rights and were/are willing to do whatever was needed to ensure their school was in the best position to win. Not only that but Texas is arguably the #1 football state from a fan interest as well as recruiting
Arizona is hella transplants...there's no State-Pride, rah rah we from AZ type of thing like there is in a place like TX. There's no live and die by football type of interest like there is in Texas, the South East, Midwest, etc.
Texas is like it's own country