Because, of course, a tomato is really a fruit.
Or is it? Enter another piece of legislation: in 1893, the US Supreme Court declared it a vegetable. What is with all this legislation trumping science and common sense anyway?
Fact is, we are skirting around the true mission: to expand the nutritional and culinary repertoire of our youth. Unfortunately, a lot of money is riding on profiting from keeping things monotonous - makes for a dependence on easily industrialized food systems. Our school systems waste good food as it stands - these arcane regulations only open the avenue for gaming by lobbyists who don't have the health of children in mind.
And I'll bet that pizza was prefrozen and tastes like cardboard.