I think motivation may be a problem, but it's a little different than you're thinking. For the second year in a row, we have a defense that is just almost nonexistent. I mean, we'll sometimes delude ourselves into thinking that they're making progress when they get an occasional stop or two against a really bad team/injured team or an FCS opponent, but if it's a team with a functional offense (i.e., at least mediocre) then it's pretty much a guaranteed touchdown every drive. If you go back and look at the 15 games we've played in the Morris era, it's pretty shocking how few first half punts we have forced. So, this then puts immense pressure on the offense, which leads to mistakes, which leads to blowout losses. We play a schedule most seasons with 4-5 really bad opponents (like bottom 30 in the nation), and those allow us to get at or near bowl eligibility, but meanwhile we're just slipping further behind the teams that are actually decent.
So, it's probably hard to keep a team motivated when the defense knows they are helpless play after play, drive after drive against half our opponents each season. The offense also likely feels unmotivated when they know that every drive where they don't score essentially means we're going down by 7 more. Hell, how could they stay motivated? As a fan it's hard to stay motivated when it seems like we have a system only built to work against 100+ ranked opponents. Even wins feel meaningless when you know you'll get horribly embarrassed against the next relevant opponent.