Dogs can be useful for services such as helping the blind, drug and bomb sniffing, police and other emergency services. A dog artificially bred will not be any less happy than a not artificially bred dog. By breeding dogs artificially you can make a dog less aggressive useful for reducing attacks.
By carefully selecting the dogs we breed, we can strengthen the characteristics that make them valuable for specific tasks. Not everybody needs bloodhounds, but search and rescue crews do. Not everyone needs a small friendly quiet dog for a companion, but many single city dwellers do. We have recently found that some service dogs can tell when their person is about to have seizure and call 911. This is clearly useful behavior and needs to be strengthened through selective breeding.
I believe dog breeders are in a business and they know which type of dogs will sell at the most profit and so I believe they should be allowed to create that breed through artifical breeding, I believe there is nothing wrong with it and the dogs are purchased by a family that will care for them.
When dogs are bred artificially for only certain traits such as being very tiny and cute, what happens is that they are too vulnerable since they are frail in ways that the dog was never meant to be and suffer all sorts of diseases and physical issues they would never otherwise have suffered.
No, I am not in favor of breeding dogs artificially because it's just flat out not natural. Sure scientists can look at breeds and draw some conclusions, but at the end of the day, it's just not the natural way of doing things. Humans should not force dogs to do things they don't want to.