Devil's advocate from a purely libertarian perspective: why pay for any of these? None are public goods (non-excludable and non-rivalrous). All are cool things to have, but is it government's role to provide them? (In fairness, with this argument, libraries nor transit would be public goods either). We need to have a very honest discussion of what benefits these venues bring, and what level of public investment is justified.
But I am a cynic. This debate will likely come down to "Well, I like sports, and we should pay for sports" and "Theatre is higher art and sports are brutish and stupid."