Also, even if it were open just weekends, they wouldn't see near the traffic they see 2 times a year. When it's a big event, people go out of their way to go there. If they were open every weekend, I still have my doubts people from NY, MI, and OH would go out there for recreation very often. In addition, you have to think about how many games you saw out of order on Sunday Vs. the ones that were down on Thurs. Nearly none were down on Thurs. Almost every game that had a duplicate, and some that didn't had games down on Sunday. Maintaining along with all the extra business hours and labor just wouldn't be feasible there.
I'd love to see it open more times a year, but I can see why it's not.