Playing the devils advocate here, but if everybody in the states excludes the tip when advertising prices, even showing a price with a suggested tip can make that place seem more expensive and thus less desirable. If a business is unprofitable or goes bankrupt, that will hurt the employees too.

I totally agree with your final point, but the masters in this case are also stuck in the unfair system. Sure they deserve some blame, but the true blame lies with the bigger fish: politicians, organisations and corporations big enough to lobby for laws that fuck over the small guy.

Also, patrons might not have a legal obligation, but if you're served by someone who does not get paid a living wage, you imo have a moral obligation to supplement their wage. Again, i totally agree this is not a fair system.