What people object to is being subjected to stupid and hypocritical political rants. People should be informed in ads that the rants will be a prominent feature of the show.
Oh, no! I agree! People should really get a warning about the things they might experience at the show. Otherwise, those who want just music might find themselves surprised and cheated by the event, which isn't cheap. If one pays $100 bucks or more for something, they should know specifically what they're paying for, and the provider should stick to the specifics of the agreement.