Those orders are made in advance, so the kitchen will be staffed for it. The place I worked at would create an assembly line that would pump out pizzas, and honestly, they're standing around making pizzas either way.
It's the big orders that come out of nowhere that get you. It can be like an hour to closing, things are winding down, there are only two guys in the kitchen because the third left... and then BAM! $200 order comes in. That's when I feel they deserve the tip more than me.
We like our food prices low and giving pay to what we feel is deserving work. I like that I have the power to stiff a waiter who gives abysmal service, and reward those who go above and beyond.