I've been a full-time musician and playing bars 2-5 nights per week for 22 years and yes, there are some idiots in bars. Guess what? It's a bar - and bars serve...ALCOHOL!!! And alcohol is a mind-altering liquid drug. Many people (obviously this chic) seem to forget that. It's not a health food store selling serving up Kombucha!
Musicians have to deal with drunk hecklers in the audience, bitchy COCKTAIL WAITRESSES, bartenders that are slow and can't make a drink to save their lives, crappy sound systems, cramped stages, getting hit on by fat chicks and occasionally getting stiffed on pay by crooked bar owners. (And that's a partial list) Bitching about it does no good though. You learn PROFESSIONAL ways of dealing with people and situations and learn that it's just part of the gig. Every job has negative bullshit to deal with. Some people can handle it, others can't. If it's the latter, then get out.
Honestly, tipping should be voluntary and people in the service industry should be paid a decent hourly wage. Tipping creates an adversarial scenario between servers and customers. In times past, tipping was completely voluntary for service that was exceptionally good, not something that was expected or demanded. If anything, servers should be bitching at club owners to pay a fair hourly wage or just don't take the job. It's pretty simple really.