One of the things I really enjoy about the Broadway shows in New York is the active participation of the audience. They cheer for every actor that comes on stage, clap at the end of every song, hoot at every exciting moment. I love being amidst the interaction between actor and audience. I love the electricity that fills the theatre. Like being caught in a cross-fire.
Audiences are not quite as spontaneous here at home. I have never witnessed a standing ovation, and I do go for quite a lot of performances. There is never that exchange of energy between actor and audience. There is never that level of adrenalin pumping.
Decency is a relative thing.