Should it be made illegal for animal shelters to euthanize healthy dogs and cats?

Shelter euthanizes healthy and perfectly normal dogs only because they cannot find a home fast enough. If the dog is not adopted in 40 day period, then he is put to sleep. These are healthy and young dogs who are just 1 to 2 years old. They have barely come on earth and their existence is ceased without them even knowing it and without even being asked. 5 lovely and sweet pit bulls were put to sleep in my shelter because they could not get adopted in 40 days. I was interested in one of them. And by the time I planned to visit the shelter to get a 2 year old pitt bull boy, I learned he was already euthanized. I felt very bad and disgusted for such an innocent life to have been taken away due to lack of patience.