It might not be organically-sources wholegrains with unicorn milk served in a hand-whittled dish of sustainable hardwood. But it's food for the hungry
I know where you are coming from, but it's the same argument that is used to stop food being improved in hospitals and why carb-heavy cheap food is the stuff of school dinners.
If our authorities, with their bulk-buying power, can't offer reasonable quality food and set a good example, who can? Kelloggs cereals are unbelievably sugary, if you eat those and some nice fish and chips followed by a super sugary huge cookie/bun/cake, which is what's on offer in my children's schools, then you have a perfect recipe for childhood obesity.
It's pointless to hand-wring about the obesity epidemic when you are in the thrall to the large food manufacturers- all of the government's healthy food initiatives involve processed crappy food (swap butter for lovely low fat margarine, why not swap your usual fizzy drinks for no-calorie ones) and this is just more advertising of the same.
I wouldn't have Tesco/supermarket vouchers in school, no Kelloggs cereals, no vending machines, no nothing. I don't believe in any of this and I can't believe schools are allowed to push this rubbish, especially the Sports Programmes where you have to spend £100's just to get a hoop for sports day. It's all the same, but this is worse as it prods the guilty conscience as there are children going hungry in the morning (which isn't solved by giving them their daily amount of sugar all in one sitting).