As I said, you can rationalize, and excuse, but just because some people cheered and weren't bothered by it, doesn't mean others were not. It's a matter of principle. And this is why I hestitated to explain. Rudeness can be subjective. What one person finds rude, another might not. I find it rude. My husband is in the music field and wouldn't think for a second to use that avenue to vent. (but then he neither drinks or does drugs while performing)
And it was hypocritical to be on drugs ranting, about people saying you are on drugs. No matter how you cut it, you should not be messed up. You wouldn't get away with it on any other job and that was his job, his customers/fans deserved to have him of sound mind when he performed.