Part of it is general bad-feeling towards the system which gets translated to the people who work within the system. They’re the visible, tangible, servicing representatives of that system, who have an expectation of additional monetary compensation directly from the customer - as much as one’s head may say, “this person is as much a victim of this system as me,” the heart doesn’t always agree.
A big part of the issue comes from growing number of people who expect tips. When the server at a counter merely moves a pre-packaged product from out of your reach to within your reach, why is there a tip jar on the counter? They are lumping themselves in with bartenders, waiters, food delivery people, etc. In a way, they are ruining it for the others.
Another part is the growing amount of the tip size.
Another part is the growing expectation that a (sizable) tip must be given, even when service is barely adequate.
The expectation of tip frequency and tip size has grown, the social stigma for not tipping has grown, and the amount of work expected to earn that tip has decreased.
Again, I point out that when I drive to In-N-Out Burger, I am greeted with the most pleasant employees who give me their full attention, never, ever, ever get an order wrong, and in general perform well above and beyond the call of duty for a fast food worker. No other chain compares. Yet they do not expect tips, and their prices are better than other food chains in the area.
Why do I go in to a Quizno’s or a Subway and see a tip jar? In those places, I receive surly service, poor quality food, and they get the orders wrong frequently. In addition, I get pressure from the manager to use alternate forms of payment, the Subways are hardly clean, and these places are often understaffed. So why do they charge more for their food, and expect tips?
It used to be (I mean in the 70s and 80s) that a tip approaching 10% was given for good service, and 10%+ tip given for excellent service. Nowadays the expectation is for 18%+ for adequate service (as stated in a previous post on this thread, 18% expectation for setting up a buffet table, they got fussy when given 10%), and some people expect 20% and more for adequate service.