It is an important idea because it is so incredibly stupid to throw such huge amounts of surplus food into landfills when the earth's resources are being consumed at such an alarming rate. On the more human scale it would make life slightly better for a lot of people if they could pick up a free sandwich or cake occasionally, and for the homeless or poverty stricken it could make their lives so much better with such little effort from big food sellers. It may be an urban myth that people could sue a company by eating their expired food taken from a bin, yet surely there is some way of altering regulations to ensure someone could not actually do this.
an example of how strict the rules of food and drink sales is that if a bottle breaks in a crate of wine and the labels come off the rest of them due to the moisture in the crate then they have to be thrown away. even staff cannot take them home despite the fact that the wine is fine, it just doesn't have a label on. I am unclear as to whether this is companies being over cautious or this is a direct regulation from the government, but either way it seems completely outrageous.
changing the law/regulations to make free food more available would be a great benefit to this country and make many people slightly happier each day.