There is one BIG reason, you're just choosing to ignore it.
BYU is taking the pandemic more seriously than you are. They recognize it as a threat to kill a lot of people. You've made the risk assessment and decided that you don't care about the risk of a pandemic right now, but BYU does care, and has made a decision to make changes across their whole campus, including athletics, to try to save lives, while still trying to let things still go on as well as they can.
They are knowingly taking in less revenue in order to save lives. Even if you don't agree that it's necessary, and you think it's a big waste, you should at least applaud the effort. They are literally putting their money where their mouth is. No offense, but I think it's ridiculously prideful that you think this disqualifies them from asking for donations.
Feel free to not help out the athletes yourself if that's your thing, and the only way you can find yourself to help the athletes is if you get a ticket to watch them. It's your money and you can choose what you do with it. I hope this pandemic doesn't do more damage than it's already done to BYU athletic.