On one side of the argument are those who say that kids who don't like white milk should have the option to drink chocolate or strawberry milk, because even though those milks have a much higher sugar count, they still deliver the calcium and Vitamin D for which milk is most valued. (And hey, they're better for kids than soda pop or fruit juices.)
On the other side are those who argue that the high sugar of flavored milks makes them an unhealthy choice that schools shouldn't be promoting. Kids who won't drink white milk should drink water, they say.
And then there are the folks who don't think schools should be offering milk at all; they claim that milk has been promoted as a necessary food by the powerful dairy lobbies, not based on nutritional evidence.
It should also be noted that the concept of milk as a healthy food has increasingly found itself at the epicenter of various food battles, whose factions range from those who say "cows' milk is for calves" and that kids should only drink soy or nut milks, to those who think cows' milk is OK, but only if it's raw, unpasteurized or organic, to those who feel that offering milk is a very efficient, cost-effective way to get calcium and Vitamin D into young kids.