I’m confused why you draw the line there but not in the first two examples. In all your examples, those people are doing their jobs that they should be getting paid adequately for already.
I don’t like being waited on; it makes me uncomfortable, even when it’s someone’s job to do it, and I alleviate that discomfort by tipping them for it. When I put myself in that situation I feel like I’m being lazy (“I could pick this up myself, but instead I’m having someone do it for me”), and it feels appropriate that I should pay more for the privilege of being lazy. The tip is my way of saying “Sorry you’re having to do this.” It’s silly, I know it is, but you asked, so there’s your answer.
I’m confused why you draw the line there but not in the first two examples. In all your examples, those people are doing their jobs that they should be getting paid adequately for already.
I don’t like being waited on; it makes me uncomfortable, even when it’s someone’s job to do it, and I alleviate that discomfort by tipping them for it. When I put myself in that situation I feel like I’m being lazy (“I could pick this up myself, but instead I’m having someone do it for me”), and it feels appropriate that I should pay more for the privilege of being lazy. The tip is my way of saying “Sorry you’re having to do this.” It’s silly, I know it is, but you asked, so there’s your answer.