Same as restaurants or movie theaters. I don’t necessarily blame the kids—I blame the crappy parents. Some will try to quiet them or at least comfort them when they don’t know how to clear their ears, but far too many just let ‘em scream.
It is amazing how quickly kids can modify their behavior once they understand consequences associated with that behavior.
Even my infant grandson has learned that misuse of his new teeth means early termination of his snack from Mommy.