Mine run more towards the performance and experience, such as

Sound support that's badly designed or poorly engineer. Louder is not better and doesn't make up for bad engineering. Pushing the sound up so loud that you can't actually enjoy the music just makes bad sound louder. What's the point of paying good money for a ticket if you have to wear hearing protection?

Bands who clearly haven't rehearsed or are just sloppy. Everyone has a bad night. I don't expect you to be perfect, but you should act like you care about the fact that I paid money to see you.

Bands with no stage presence. Musicians are, among other things, entertainers. Don't phone it in. Be engaging and look like you want to be there.