"You sing what you want. You say what you want.
And if someone doesn't like it they don't have to listen."

Yes. And if you have a repertoire of songs so hateful that all your audiences walk out, you won't get very far.

Equally, not only do they not have to listen, but they can also elect to slow-handclap you, greet you with a sustained stony silence, heckle you or boo you offstage.

These negotiations are what makes live music situations superior to recorded music albums: performer/audience interaction, which is in my experience more common in folk clubs than at rock gigs.

Ususally it's of the genial variety, but that's not to say that an edgy or tense situation is a bad one.