There are literally laws that say you can donate with no liability. It's a common misconception that is too pervasive even in those who are in charge.

In fact, the ones who do realize they can do it with no liability have calculated the costs of throwing away(trash removal is subsidized) vs creating an entirely new process for donating food and worry about its handling(vs. The very lax and rough handling trash gets). Not to mention that they will have to move it to a separate location as it can bring unwanted traffic that is not profitable.

Donating is not an easy task. It's a burden, and there isn't a public service to make it easier and similar in cost to trash removal services. It's not the company's fault. It's the government and charities that are not getting involved.