Is it right to ask all breeders to curb breeding in areas of over population?

I am sadden by the reports of dogs being killed because there are not enough homes to care for them. The Pit Bull is a good example. In many cities, they are killed because they are pits and hard to place. Is it right to require pit breeders to stop breeding until the problem is solved? It makes sense, but I don't want any breed of dog to disappear and we need good breeders to keep them around.