Class and Thanksgiving

Here's my little run-in with class issues over Turkey Day:

My aunt works as a server at a fancy restaurant. Catering to the non-culinary types, this restaurant was open on Thanksgiving, and thinking that the tips would be awesome on such a holiday, my aunt decided to work a double shift. When my aunt called us later that night, however, she reported a not-so-pleasant customer experience. Apparently, the tips were stingy, the customers rude and the overall demeanor depressing. I definitely thought that the atmosphere would be very festive and family-like because of the holiday, but it seemed to be just the opposite. It got me thinking: did people look down upon my aunt even more so that night because they assumed that if she was working on Thanksgiving, she obviously needed the money and that she was likely from the lower class. Or possibly that she didn't have a family or friends to go home to so that meant that she didn't need as much tip or to be treated civilly? Waitressing is such a classed occupation as it is, and it was interesting to me to see how the time/season (Thanksgiving) made it even more so. Any thoughts on why her customers acted like this? Is it just the nature of a bunch of grumpy people who don't have a homemade turkey dinner to look forward to? Or is there a stigma associated with those of us who have to OR CHOOSE to work on a holiday?