Well, yea. Most people view animals as disposable. I think it's unfortunate they're that out of touch with creatures that have so much life in them but you can't fix that for them. People either "get it" or they don't. My brother is that way, he's just never connected to them but I don't begrudge him it.
I've had two dogs and five cats in my entire life, never have I 'replaced' one. Whenever one passes I don't just go pick up another. In some small way when another pet comes into my life they help fill a void (in much the same way that having another child would fill the void of a lost first one), but each one is different. Our first cat was a matriarch, unshakable but kind of distant. The second was a wild boy, always hunting and fighting. The third we hardly knew, he passed just a few days after we found him on the road outside our house one rainy night. The fourth is a scaredy cat and a little crazy, she hisses at her own tail and hardly leaves her 'comfort zone' rooms. The fifth is another wild boy, but listens well considering he was a stray in town for the first year of his life.
I get that you don't "see" that in your pet(s), they're 'objects' distinguishable only by the color of their fur for your families amusement or however you want to term it. That's fine, but you calling them all the same and replaceable is kind of like me saying all babies are the same because all they do is cry and poop and have no personality and all look about the same. Which I don't actually think is true, I just haven't had the experience yet. I wouldn't belittle a person for seeing that in their kid though.
People that are involved with raising their pets have just as much of a 'real' experience as someone who is raising their kids have, just different challenges and needs. Raising kids is the triathlon, raising a pet is the 5k.