Bad tippers are entitled, needy nightmares who bleed the smiles and energy out of unsuspecting servers and bartenders only to leave them nothing in return. Sometimes, when you ask a bad tipper why they have adopted such a shameful habit, the response is: "I don't think they work hard enough" or "I don't believe in tipped wages, they should just get paid a living wage."
All of these arguments are psychopathic, empathy-deficient trash. Of course, you have no idea how hard they work and even if you think their job is easy--don't they deserve a 20% tip for placating your bratty kid when he screamed about the chicken nuggets not being crispy enough? If you don't believe in tipped wages, that's a fine belief to have, but you're not going to change a system that's been in place for years by stiffing your teenage waitress at "The Olive Garden."