It does sort of raise the issue of this being a captive audience. If the dining hall at my college suddenly went vegetarian, I would have pretty much had to go

It does sort of raise the issue of this being a captive audience. If the dining hall at my college suddenly went vegetarian, I would have pretty much had to go along with it; it's the most convenient option, and often the only real choice to get something to eat between classes - going off campus would take too long. And then there is the case that your meal plan is only valid there, and in the case at the school I went to, you could not opt out of paying for the meal plan even if you wanted to, so you'd be flushing $500-$1000 down the drain.