Are people who say they have pets, but the "pets" are fish, weirdos by nature or nurture?

Pets are basically any animal besides a human kept in an artificial habitat and is cared for by the owner human. Lets look at dogs: Live in houses: artifical housing. Domesticated by human? pet. Fish: artificial housing: aquarium. domesticated by human? pet. You can call a lizard, parakeet, cat, or anything a pet, why not a fish?