Well the shoot I'm part of, everything that's edible gets shared out and eaten. So sweeping statements such as yours aren't helpful. Yes, there's some, especially the big ones where that's different, but there's hundreds of small farm/local shoots all over the country where the bag is shared out, taken home and processed as food. In recent years I've been part of 3 different shoots and nothing goes to waste (except perhaps the odd smashed up pheasant and even that is generally taken by someone for their dogs).
In this country's atmosphere at present, trying to diss other shooting sports like this is only shooting each other in the foot. Divided we fall!