There is a significant portion of the general population that would go without medical care if people kicked them out the door for being rude. They still need access to services. Respect is something that some people won't give you unless you earn it. It's kind of funny that some pharmacy staff members expect instant respect out of patients, but offer disrespect if they don't get what they want. Or, maybe it's more sad than funny. I don't know.
I do not consider myself to be a doormat. In fact, I get "walked on" much less than many people who are eager to assert that they are not there to be "walked on". That is because people see that I am there to help and decide that I am not the person they want to direct their anger towards. By being proactive, I don't generally need to assert myself and put the patient on the defensive. The exception comes if someone makes a personal attack on me. If they are just generally cranky, I am not going ot stoop to their level and chew them out. That would validate their negative attitude. And, if I put someone on the defensive, I can hardly expect them to be amenable to good relations in the future.
People aren't mean because we allow them to do so. If that were true, people who assert that they should be respected by their patients would never have to deal with disgruntled patients. This is hardly the case. People are mean because we haven't established a good relationship with them...yet.