I agree that it's corrupt. But I think it should stay. In fact, I think they should expand it. Doctors, sales clerks, and elected officials should work for tips too.
How many times have you had a doctor be rude to you, not answer all your questions, and not spend nearly enough time on your problems? How often have you been ignored by the grocery clerk, or watched the stock boy you want to ask for help texting on his cell phone instead of helping customers? How often do you complain about your elected officials misusing funds, lying about everything, and engaging in activities that would land you in jail?
And yet all of them get paid exactly the same, whether we're happy with them or not.
I like being able to tell at least one person in the world how well they treated me, in a way they understand. You were friendly and helpful, and got me what I wanted? Big tip. You were rude and ignored me? No tip. Easy for the wait staff to tell if I'm happy or not.
Wish other professions were hit where it hurts when they suck at their jobs.