I understand your frustration with this particular person, but your generalities simply aren't fair. There are people who are disabled and unable to work who are able to care for a dog and for whom a dog is a reason to get up in the morning. There is an old man in my neighborhood who can't walk more than ten feet from his scooter, and he has an old dog who rides in the footwell. I'm not about to tell him that if he can't afford $30 a month to feed the dog and $20 for some painkillers (poor thing has really bad arthritis) that he should just get rid of it.
Yeah? Well if he starts bitching about how much money he has, I sure as hell am. I won't bat an eyelash at telling someone who is living on my nickel and complaining about it to go and pound sand where the sun don't shine if they have any luxuries whatsoever. You're old? Well, you had plenty of time to plan for it. You're in a scooter? You almost certainly went through one of the scam companies to get it and I paid for that anyway. You got a dog? Great. Figure out how to feed it your own fucking self; I ain't giving you any more money while you are maintaining a fucking pet. Grow the fuck up and get the fuck over it. There are scads of rescue organizations out there who will make sure that Fido gets a good home, but if you can't feed yourself, then you don't need to be spending my money to feed Fido.
Olde-style, states' rights conservative. Ask if this concept confuses you.