"No Problem"

Does anyone remember when 'please' was answered with phrases like 'you are welcome', or 'it is my pleasure'? Today, the courtesy of thanking, say, a waiter as he or she delivers food to one's table is often answered 'no problem'. I must say, that it is a very lucky thing indeed that it is 'no problem' for a food server to serve food. Imagine what would happen to a restaurant if it suddenly became a problem for food servers to serve food. And what is the tip jar at Starbuck's for? Not spilling coffee on me? I understand tipping the person who hauls my heavy bags up to a room, or who brings a salad, main course, beverages, etc to my table. I understand when my hotel room has been well maintained during a visit, or when I have left a mess for the housekeeping staff. But why am I expected to tip counter people where I do all the walking (order and pay here, pick up there, add cream or get a napkin there)? In fact, I sometimes find myself wiping off the counter where the cream and sugar are housed - instinctive action I guess. Should I be tipped? Oh, and I even understand tipping cab drivers - it is an incentive to them to make sure that I arrive at my destination alive. One dry cleaner told me that broken buttons as a result of laundering or ironing were not repaired. He seemed puzzled by my suggestion that the larger purpose - abjectly defeated by missing and broken buttons - of having shirts cleaned and pressed was in fact to make them more presentable. I have a new cleaner, but am waiting for the day when a tip jar appears there.