The ASU bit killed him on the recruiting trail, just as the Baylor incident hurt Morris. The other thing was that he lost his big recruiters (Klemm, Rhinebold) and didn't replace them with quality coaches/recruiters. He complained about not having other support from the school, but the reality is that they supported him light years more than previous coaches.
I don't think he was here for the paycheck. It was an ego play. He wanted to show people that 1) he could turn around ANY program, 2) he could recruit on a shoestring budget and do things his way. And then use that to get a higher profile job. But it wasn't a money thing, it was an ego thing.
The only other thing I would add is that I think June didn't start to "look down on" SMU until after that UCF game. Phillips looked down on SMU from the moment he got here, and Morris pretty much did the same, which is why he was so quick to talk to Baylor.
Tom Mason struggled as a head coach, but I have tons of respect for the guy. He never said anything but positive things about SMU, loved it here, completely bought into the whole thing.