I’m pretty sure it’s a space thing. How many millions of people in New York live in half a closet, where your “home” is the place where you sleep and recharge your phone, and you spend every waking second out and about in the city. You don’t have a kitchen much less a dishwasher. Meanwhile I’ve never seen a double wide mobile home without one equipped from the factory. I would be surprised to find a multi-bedroom family dwelling without a dishwasher.