I voted for a little of both.
On the hobby side, we are collectors and we are often builders and crafters as well. A new fish for me is like a new craft project for me. If it doesn't work I have no problem trashing a new fish, ie... trade, give away, sell or euthanize if needed. I would never have done any of those things to a new puppy because it was little tough in the begining.
On the pet side, I have some big cichlids that I'm quite fond of now. If I came home and my big oscar, texas, myan, or pink tilapia was dead I would be very unhappy. I spend time with them everyday, and we interact with each other.
Naldo