It’s a different culture. In America, “the customer is always right.” That’s not literally true, but the general approach is that the customer, the one bringing the money, is the boss and his reasonable requests should be hastily fulfilled. That authority is reflected in the power to set the tip. In Europe that is emphatically not the case, especially outside upscale establishments. America is actually drifting toward Europe on this point, with millennials being less willing to complain or to penalize in the tip. But a wide gulf remains.

In some other cultures, good service is considered more of a moral obligation. The shame of providing bad service and of being known for it keeps waiters and their managers on their toes. Different culture.