My guess would be they didn’t think they’d be charged, since they kept sending food back. I’ve seen this before plenty of times - ‘professional complainers’ who think that if they put up a big enough show, they’ll get their bill greatly reduced or even comped. The waitress can forget about any kind of tip for having to put up with them as well.
And yes, there is a certain segment of the population that does this more than others.
This is my complete lack of surprise - :-I
“...professional complainers who think that if they put up a big enough show, theyll get their bill greatly reduced or even comped.”
Worked for years for the DemoRats and their constituents.