Exactly. People have it in their minds that flight attendants are like waitresses of the sky, there to serve them. They are, in fact, part of the flight crew and have broad authority over the operation of the flight and on flight safety. The FAR is pretty clear about the role of an airplane's flight crew and consequences for interfering with that role.

Also, the fact that some people treat waitresses and service workers as punching bags that are "beneath them" socially, is a separate but related problem here.