I'm thinking the food is probably better than the kids are making out. Schools don't need Drama Departments to have little Drama Queens (and little Drama Kings).
When I was in High School, the food was rarely great, but it was always edible and reasonably tasty. I think these kids are just being cranky because they can impress their friends.
All kidding aside, I remember a hilarious lunch hour when one kid commented on the instant chocolate pudding, saying, "It all comes out of the same can." As soon as the double meaning of "can" became apparent, it was a rollicking good time as the remark spread across the lunchroom.