I don't have an issue with people not wanting a pet, that's just a lifestyle choice and I wouldn't judge them for that any more than I would judge a person for not wanting children. Sometimes people's circumstances/health/location/career choice plays a part in these decisions.
What I don't like, however is the tone of moral superiority from anti-pet people. They always start banging on about veganism, caring about the environment and the anthropomorphism of pet animals. No matter what you say in response they shout you down because they are right and you are wrong.
These threads always go the same way and it's pointless trying to say that you have a dog but you're also a vegan, you have a garden full of trees and plants that encourage wildlife, that you put up bird boxes, don't drive a monstrous SUV or fly abroad twice a year. Or that you have a dog but don't frequent coffee shops, that your dog doesn't wear clothes or have a pram or get referred to as a fur baby. That it's never been to a beauty parlour, doesn't get its own advent calendar and that it is being reared in a way compatible with its instincts.
Because to the anti-pet people, all dogs are inbred, deformed, smell of wee, are called Fifi-Trixiebelle and live on cream cakes. Anything else disappoints them.