The point is this:
Waste not, want not.
Why knowingly allow something to be put on your plate if you're not gonna eat it?
It's wasteful. Nothing more, nothing less.
So, if the biscuit they already made (or the dough already prepared) isn't put on your plate it isn't being wasted? I'd think the restaurant knows that on Tuesday they need x number of biscuits so that is what they make.
I guess if they start giving away extra biscuits at the end of the night, you've made a difference. The only food place I've worked at insisted on all leftover food being thrown away. They didn't want the cooks and employees cooking extra in order to eat it later.