I think this is a good discussion so long as it remains civil! I tend to agree with Sluggo on his comments.
That said, here is my opinion and experience. I own two cats, three rats, a snake, and am working on my aquarium, previously I had a saltwater tank.
For the cats, rats, and snake, I provide for them to the best of my ability, and try to cater to the needs of the species because I made the decision to own and be responsible for the pet. Once my aquarium is going, I will be making every effort to provide for the specific needs of the fish, based on my knowledge and understanding.
Now if for any of my pets, I am unaware of a specific need when I first get them, and then find out about it at a later time, and don't, within a reasonable time rectify the situation, I feel like that would be knowingly neglecting them.
For instance, when I got my corn snake, I bought a simple pre made "snake kit" for her, and set it up. Later I went online, and found that corn snakes benefit better from having an under tank heater on a thermostat which would keep a portion of the tank at a specific reasonable temperature for them. Within a week of the snake purchase, I had attached my nice new under tank heater and plugged it into my new thermostat. I took care of the needs of my pet, because that is the logical, reasonable thing to do.
I fully understand making "impulse buys" and starting out all wrong for a pet, just not knowing they have a higher need... But once I find out I'm doing something wrong for them, I fix it. I feel anyone should...
When someone else owns a pet, if I see they are neglecting the needs of that pet, I may try to politely point it out to them, but ultimately where they go from there is up to them. I would never try to liberate someone else's property because I feel they are not owning it right hehe, however I wouldn't just sit quietly either.
Hope that makes sense.