Why do some people buy their dogs from breeders?

I can understand people who buy from breeders because they want to compete with their dog. Or those who have some kind of lifestyle that leads them to prefer one kind of breed, for example they're active people and want a dog they can go camping or running with. And those who have young children and want a dog with a gentle disposition. But other than that? Those people who adopt purebred Pugs or "Yorkiepoos" simply because they want a dog that looks a certain way? It honestly just makes me sick.