It makes sense to me. Univeristies (aside from some of the most prestigious/well endowed, and even some of them) operate like any other US business. Students are the customers and if you don't have customers you're not going to survive.
The option for universities not opening is to move to remote learning models at which point you're now competeing more directly with other online universities as well as a wider range of traditional brick and mortar universities. You're also competing with mountains of online information available freely for many disciplines in a world where a college degree is being devalued. Many universities were already starting to struggle to meet growth expectations, COVID exacerbated and accelerated this issue.
So just like every other business foaming at the mouth to get revenue streams flowing again as a primary goal to remain competitive and succeed, colleges are following suit. Other factors are considered secondary to those restarts.