Gambling has the extreme potential to warp incentives for players and coaches due to the close nature of the sports community at colleges. This in turn threatens the trust that fans have that incentives will not be warped into throwing games or throwing scoring attempts or whatever else can be get bet on. Harming that trust threatens reductions in fan base and alumni support as well as negatively impacting school reputation / branding.
In addition, I’d like to think that colleges still care, a little, about good character development. Creating an environment that breeds collusion / corruption goes against that goal.
Thus the rules. I agree with them and their severity. The rules are extremely easy to abide by.