Holidays and Loneliness
I realize their are plenty of people who want to be with their families, but are put in a position such that they have to work if they want to keep their jobs. And that's a horrible thing. But there are plenty of people who want to work. The holidays are hard enough for them as it is. By working, it helps them forget how alone they are. There are people for whom the only conversation they will have on Thanksgiving will be with the waitress or the cashier. If you want to know more about such people, you can check out the previous years' holiday suicide statistics.
So yes, it would be nice if the stores and restaurants were all closed on Thanksgiving Day. But it would also be nice if there was no one alone that day. Do you befriend people like that? Do you open your home to them? If not, then I'm not sure you have any right to tell them how or how not to spend the day.