Other posters are likely correct in that it has something to do with what country you are in and the laws there.
However, in some situations at work I have some leeway in how things are handled. If I have a customer bring a complaint to me and they are patient, willing to work with me, heck even just say “please”, I’m probably a lot more likely to go above and beyond. If they are rude and condescending I will still do my job but won’t make the effort to go above and beyond. The way you’re threatening to play silly games with the crews tips make it seem like you’d fall into the latter category.