I agree that the general public should not have to pay to use a
facility supported by their tax dollars.  The question is, is the
general public willing to actually support those facilities, at whatever
tax level is necessary, or is it merely willing to subsidize them?
The latter is the case in California, where the Chancellor of UC-Berkeley
has flatly stated that we are now a state-subsidized rather than a
state-supported university.  In this regard, it is really up to John Q.
Public to determine if museum etc. facilities should be supported by taxes,
by individual users fees, or by some combination of the two.  Ideals are
great, but they don't pay for salaries, buy supplies, or pay the electric
bill.  Remembering that we are all of us members of the tax-paying public,
I quote the immortal bard, Pogo: "We have met the enemy, and he is us".