I have picky eaters too, one won't eat any veggies so I always double her fruit and she does like the protein and grain products. I always serve two veggies for lunch and give her a teaspoon of each every day hoping for a miracle. Then I have a boy who won't eat food that is combined. Even when I cook a roast and carrots and potatoes in the crockpot he knows and says it smells funny. I tell him that he has to try everything or be hungry for the same reason you said - I run a daycare, not a restaurant. Today that is what I cooked in the crockpot, then I dumped it and drained it and rinsed it all. For pete's sake!
I'm honest with the parents every day about all the food that is offered to the children. If they don't eat it they aren't going to starve. Hopefully they will eat lots of dinner in the evening. It used to drive me crazy but now I start with really tiny portions and give them seconds if they want them, then I don't have to put as much food into the garbage.
So Starshine and Ashleigh, I agree with you both completely.