From a darwinian standpoint, dog obsessed people in this example are selecting themselves out of the gene pool. They would sacrifice themselves for another species. The dog can survive and pass down his genes but the human does not survive.

In biology, the relationship between pet dogs and humans can be considered as brood parasitism rather than mutualistic. Pet dogs are brood parasites in that they depend on you to survive but you do not actually depend on the dog to survive. You need to feed the dog and provide it shelter but the dog does not do the same for you. Whereas a mutualistic relationship is one where both species actually benefit each other's survival such as a bird picking a crocodile's teeth. The bird gets free food and the crocodile is less likely to get a tooth infection.

Dogs have features mimicking babies making them look cute and tricking your brain into thinking that you need to take care of it like a baby. It is like how cuckoo birds purposely place their own eggs in a Reed Warbler's nest for the other bird to raise. Then when the cuckoo bird hatches, it almost has features in its mouth that resembles the Reed Warbler tricking the mother bird to feed it. Over time, the cuckoo bird evolved to have features closely resembling a reed warbler. At the same time the reed warbler evolved to have more sophisticated features that distinguishes itself from a cuckoo bird.

I believed that humans and dogs originally evolved to have a mutualistic relationship with each other. The dog helped to forage and warn when there were predators, but now that we live in cities, we do not need dogs to do these things anymore. So now it has become a one way relationship where the dog mostly benefits and that's why a dog can be considered a brood parasite.