A Boring Dystopia

What if they were against giving the food away?

Then they're malevolent, and thus unqualified for their position. If someone are faced with the choice between giving something away in a way that can benefit them, and just setting the thing on fire purely to prevent someone else possibly benefitting, and they choose the latter, they are unqualified for any executive position. Even if one assigns no value to the potential of helping others, they are actively choosing to lose out on almost certain benefits (through tax benefits, PR, reduction of thefts of necessity, which are appreciably likely to come from their store's saleable stock rather than their waste) to prevent possible, but improbable, losses. That is actively choosing a worse outcome for the company they are ostensibly working to serve. Failure.

what if their worry is that someone would hide the stuff till it expires to give more away.

Then either:
A) The person is committing malfeasance and can be audited, as all managers should be anyway, and fired for actual harm, (which is still unlikely to cause enough damages to actually be a threat to the company, because if it caused an appreciable dip in profits, they'd fire them for incompetence without even needing a detailed audit)
or B) they can demonstrate to the management they are doing something that actually works out in the favor of the company, and the halfwits would be firing someone who found a way to turn trash into money.

It is idiotic mismanagement to throw away someone with years of experience because they might do something that most people wouldn't think of. Even an unpaid intern has enough access such that they might choose to misappropriate something of value. If you fire everyone who might take advantage of their access for misappropriation, there will be no employees, just a building stripped even of its copper wiring because you couldn't trust a security guard to have keys.

Most managers don't get the discretion to break protocol when they feel like it.

This is a statement of current failure, not a reason not to improve. I'm saying something like 'It's a bad idea to cut your hands with a knife,' and your response is something like, 'But in all the kitchens I've worked in, people cut themselves all the time.' Something bad doesn't become good just because it's common. If a job can be accomplished just blindly following a list of prescribed rules and procedures, that's a minimum wage job or a job in need of automation, not an executive position for a human.