We need to understand something about the Manziel family. They are not merely wealthy. They are filthy, astonishing, rich. They have Texas oil money, and when we're talking Texas oil money, we are talking about billions and billions of dollars that lasts for generations, and will likely never run out. Ever.
Johnny likely doesn't care because he likely has a trust in which he'll eventually inherit $100 million or so in a few years. He he doesn't care if he makes it in the NFL because he'll still be a rich douche that can do whatever he wants. AND, he'll be able to be a multi-millionare without putting his body through a career as an athlete. The guy is a lazy, entitled douche, and doesn't care about anyone else.
It's sad, but, it's probably how he thinks.