That stinks of the naïve hippie nonsense of "we have so much food, man, we could feed the entire world easily, but the MAN won't let it happen". Turns out real-life logistics and safety regulations makes that a pipe dream.
I've worked in the grocery business for a long time, and have had to get food safety certifications on several occasions. At competent stores, if someone returns a refrigerated or frozen item after it's left the store - even if it's still unopened and cold - we have to discard it, because the cold chain has been broken and we can no longer verify the amount of time the product's been in the temperature danger zone for pathogen growth. The same applies for hot foods, or even just items with non-sealed packaging (like bread), because the store can no longer vouch that the product wasn't tampered with once it was out of the store. As for expired food, knowingly selling product past its sell-by date (not to be confused with "best by" date) will very likely result in serious regulatory consequences or legal action.
(...this is a "in a perfect world" sort of thing, because I know a lot of shitty stores/chains do this under the radar, but COMPETENT stores do not chance it, and I wouldn't ever work/shop at one of them. Hell, I've had to report some stores for violations that you people wouldn't want to believe.)
The vast majority of these products are totally fine. Even most expired foods have a fairly healthy amount of wiggle-room as long as the cold chain procedures have been followed properly. But the risk of someone contracting a foodborne illness from non-controlled or potentially-tampered product is unacceptable, because even one severe case can get a store shut down, liable for lawsuits, and terrible publicity no matter what the inevitable legal outcome is (turns out that poisoning your customers is bad for business, for some reason). A lot of stores either don't donate food at all anymore, or only donate "safe" things like damaged (but not breached) canned goods, to avoid the risk of foodborne illness and liability for the consequences. Is it a waste? Often, yes, but it's a risk we simply cannot take, considering the seriousness of many foodborne illnesses.
If Jim's able to devise improvements to cold chain procedures, invent new food sterilization techniques that are scientifically proven and can be used cost-effectively at the store level, rapidly improve transport time to maximize shelf life of fresh product and get more near-expired food to charities before it becomes a health risk, or even just change liability laws so stores don't have to fear lawsuits from reselling returned cheese, he's welcome to submit those ideas to any grocery operation team, and I'm sure they'd pay him well for his contributions.
If, however, he's only going to use it as a punchline in his stupid anti-capitalist babbling, and make it sound like grocery stores surround discarded product with plexiglass walls and laugh at starving orphans trying to get a bit of stale bread, he is welcome to go fuck himself. Grocery doesn't discard food to punish people, they do it so people don't die, you fat fucking twat. One of the most important principles in food safety is that every foodborne illness is preventable, and you don't prevent it by letting people chow down on product that you can't verify is safe.
Clearly Jim hasn't been missing many meals, so I'd have to ask how much he's donating to the ol' food bank when he's not criticizing businesses for trying not to get people sick or dead...
...and I'm sure that if a store had unsecured food waste around the back and some homeless people died from eating it, he'd be calling them irresponsible for not having paid guards to watch the back 24/7, too. You can't win with these hippies.