Is it though? What if the food quality is really low? As the article states, it's a place to get rid of some old food items. Do you think you have an obligation to eat it no matter what?
Anyway, if you don't want to pay for wasting things you don't like, make your first plate a grazing/browsing sampler platter, then come back for the stuff you liked.
Even in a case of "sampling" and finding things you didn't want to finish, you'd be charged. There can be a reasonable alternative.
Only if you put it on your plate ;)
No, just pay for the waste.