“That being said, why is there a deficit in their accounts?”
1. Many parents (probably more like a parent) are just lazy and don’t refill their kid’s account.
2. School worker are incompetent, even by government employee standards and don’t always tell the parents the account is low. And the schools are food fascists so the kids can’t just bring their lunch anymore.
This times about a million. My nephew had trouble multiple times because the school had two different accounts, one strictly for lunches and the other for "incidentals" - which could also be used for lunches. So my brother just kept that one full in case something came up and didn't bother with the lunch account. My brother had to argue with them about every 2 months when they'd refuse to look up the other account.