Seems to me that requiring people to stand at attention and listen to a "national anthem" before watching an entertainment event is more suited to the old Soviet bloc states than the "land of the free".
Like many other things, people have gotten so hung up on the symbolism that they can't even remember any other way of living, IMHO.
No one is "required" to stand at attention and sing the national anthem at any time. During the playing of the anthem you have the right to remain seated, go get a soda, read a book, whatever. It is always a request and the announcer usually says "please" stand for the singing ...."
May you live as long as you wish and love as long as you live.
Robert A. Heinlein