A tip is additional compensation for great service solely at the discretion of the passenger.
If cab drivers expect a tip regardless of service quality, then the tip might as well be added to the cab rate.
If cab drivers expect a tip regardless of service quality, then the tip might as well be added to the cab rate.
Yeah, it should be, shouldn't it? But it isn't. The system is fucked, of course, but it's fucked in a very deliberate way where "protesting" by not tipping hurts the cabbie significantly, and the people responsible for the system not at all.