I worked in a fast food restaurant here in the States, people tipped but usually not well. I wasn't pressed about it, I was getting a full minimum wage. Entitled customers didn't give me trouble for whatever reason, they seemed to size up my coworkers as softer targets.
> Why?
I was just curious about how OP's experience informed their perspective.
When visiting the States I have observed on a couple of occasions where a customer shouted at staff and used the threat of withholding a tip as leverage to be unreasonably nasty to wait staff.
The service industry in the US is awful, and the tipping culture is really toxic. I don't understand those that defend the American approach.