I think it's a push back against the anthropomorphization of animals. To such people, "family" is limited to human beings.
Although I'm a crazy dog person and think of Kimber as part of my family, I do understand the other side. On another site I visit, a woman had just started working at an office which was dog-friendly. No one had mentioned in the interview that people often brought their pets to the office, and she hadn't seen any during the on-site visit. This was a problem because she is horrifically allergic to dogs. She tried working with her allergist to come up with alternatives and ways to keep her exposure to the dander at a minimum, but really, she was so very sensitive that her health was suffering. (This workplace had nothing to do with animal care.) Some on the commentariat were very unsympathetic: the dogs were there first; people liked bringing their dogs to the office; she should find another job. I was somewhat sympathetic to this response but really, dogs don't have the same rights as humans. Where we draw that line is an interesting discussion.
I'm not saying that's how you are, Snowshoe! It's just an example of how I've been thinking about this topic..