If you're referring to me, I've been scoffing at movie prices since they hit $6.
Not relevant, I know, as your point is that peeps pay money for other "entertainment," so why not for visits to national parks?
I don't see "nature" and the environment we live in as entertainment. It's the basis, an essential; it meets a human need (although, if you follow that line of argument, shouldn't all sex be free?). Parks are concentrated natural environments, set aside for respite, etc., in an industrialized society. I don't see it as a commodity to be purchased. But apparently that is the way of the future, and the now.
BTW, the high cost of gas is precisely one of the reasons park entry fees should *not* rise.
But, whatev. Nobody asked me, eh? Carry on, then.