Ah, you touched another nerve.
You see, I was a restaurant owner at one time (as a result of a misguided idea after retirement) and when I tended bar - was I still the owner - or was I the bartender (who had the night off and who had made more than me that week when you add his salary AND tips)???
Anyone in the "service" industry relies as much on tips for their bottom line as they do on the fees they charge because as Dave56 points out, if they doesn't keep the fees down, you will go to someone else.
When we were in India, we hired a private guide and hired a car and driver from the hotel. We not only paid the guide, we bought him and the driver lunch, mid-day refreshments and tipped them both 10% each of their respective cost. But then that's me!