I believe I answered your question. Ever answer a question in an analogy?
They are humans, yes, but they are also charged with the public interest at heart.
You can't put on a badge and instantly acquire respect.
As I said before, if I were in Gates' shoes I would have been a lot more cordial and swallow my contempt.
I own my business, the property, the building, and all of the equipment therein.
If a person is displeased with my work, which would be the only reason a person would be allowed in the shop area, I would most certainly take the high road. I'd let the man/woman finish their little rant, ask them if they feel better, and then ask to be paid for services rendered.