Calling school cafeteria food healthy, at least when I went to school, would be something of a mis-statement, if there were vegetables they were pretty horrible canned vegetables, you had hamburgers and pizza and hot dogs, and not very good ones, the infamous "mystery meat’ and if you had pasta, it was more than likely canned (and this was suburban NJ, not inner city Newark). In high school it was a bit better, they had salads available, but still a lot of the food was heavy on fat, salt, and they had things like white bread.
What was even worse in a lot of schools fast food became the true staple, school districts made deals with the food purveyors, and you had things like chicken nuggets and the like, and they had things like Snapple Iced Tea and Soda as the main drinks, basically they outsourced the cafeteria to fast food.
I haven’t seen the school lunches they are serving now, but in some sense it does sound like what is typical, to create healthy menus they go overboard. So they take out salt, but they don’t replace it with other spices, and they start serving chicken franks and the like that basically are tasteless (I have tried many such items from the store, and what is worse, I would bet what they are serving is not anywhere near all natural, it is probably loaded with chemicals). Unfortunately, what I suspect you are seeing is schools in order to meet the guidelines have done so without trying to make it palatable, there is a reason that "health food’ often has a bad reputation, and it is frankly that it is often created with a goal of being ‘healthy’ rather than "tasty’ (Julia Child used to go off on that, and rightfully so, and she was proven right that a lot of the ‘health food’ was not very healthy, the whole no cholesterol/low fat to protect the heart, that salt was necessarily an evil, or even better, that somehow margarine and hydrogenated vegetable oils were
‘better’ than butter). I don’t blame Michelle Obama’s initiative, not when schools were serving fast food, but the problem is no one probably bothered to work on coming up with sample menus with recipes for healthy, nutrititious food kids will eat.