Is the world ethical? No. Is speutering ethical? I believe so. Should some people not have children? Yes.
I'm unsure of what your point is. Is it that you don't think breeders should be in business? Have you ever purchased a purebred dog? Perhaps you should make a point of shadowing a truly ethical breeder and check out the amount of dedication and work that goes into raising truly purebred animals.
Whatever you are.....be a good one.