it's because of the dog.
my neighbor has a lanky black lab and i have never seen the neighbor walk her farther than the garage or the dumpster. i have never seen the neighbor put the dog in the car and take her anywhere.
every morning the neighbor opens the door and ties the dog to the railing for long enough to pee. grass won't grow in front of the neighbor's condo, or in front of mine as far as the dog's tie-up reaches.
when you buy a puppy, you are buying a living creature with needs and desires. dogs like to go places, sniff things, and did i mention GO PLACES? a dog needs exercise and company. the neighbor leaves this dog alone all day nearly every day.
but the neighbor has a nice flowerpot with the dog's name on it, and at halloween carves a pumpkin with the dog's name in it.
because, you know, a dog really appreciates personalized accessories.
i think a lot of people like the IDEA of a dog more than an actual dog. same goes for kids.
if you don't want to spend time with a dog, play with it, give it exercise and attention, you should not have a dog.