The thought is that since exceeding the expiration (or more accurately, the quality) date of the ingredients (for example, tomatos) renders the finished products as substandard in some way, its frankly kind of a dick move to serve food you wouldn't sell to paying hungry people to any hungry people let along poor hungry people.
Quality dates are a big part of spoilage in the food service industry, so the quality departments in all of these organizations try to min-max the dates to best represent their required quality, and of course their requirements are longevity, palatability and mostly sales.
If an otherwise reputable food retailer begins serving a secondary market with what is definitionally substandard products, it opens a large and murky doorway to liabilities extending far beyond a mere lawsuit. What if the next kitchen mishandles the food and serves gross food to people in need? Even hungry poor people will dislike week old, vinegary tomato slices.
There is also the possibility of cross contamination, but in general it is just best to avoid being one local news reporter away from revealing that FoodCo got $foo tax write off for serving mushy tomatoes to old people.
A better use of this resource would be to transfer the wasted or spoiled food to a facility which creates compost for local residents or farms.