The only fanbases that are rational are those (like you mentioned) who are so beat down that they expect failure.
And those fans who rationally can expect to be national champions basically every year. I have a buddy who is a long-time Alabama fan. And the expectation every year is that they win the title. Which is...not irrational.
And the college football season is not a joy for him. There's only one or maybe two games he really cares about before the playoff. Every game is just a chance to slip-up, never to do something exciting. Even when they win the title, it's more a sigh of relief that expectations were met than any sort of joy at doing something amazing.