I would imagine it’s less about the possibility of other healthy choices and more about not putting more things on the overworked teacher’s plates (so to speak). Which is the faster way to tell if kids have a healthy snack: seeing a row of kids eating fruit, or going to each one, looking at the snack’s wrapper, figure out if the ingredients sound healthy enough, hope that you’re not going to have to get into an argument with the kid because their parent found a couple of research papers on the internet, then move to the next one.