Bingo. Same as "tiny homes". They're not solving a problem without an existing—possibly even superior—solution. They're just solving it in a way that doesn't offend one's class self-image. Modular homes, prefabs, trailer homes, RVs, all already exist and have for a long time—but they're associated with he wrong sorts of people.
80% people who want the ease of setup of a double wide but really, really, really want to visibly distance themselves from the stereotypes and can afford to pay a premium and give up a lot of square footage to do so. (There's a reason this is on the front page of HN.)
20% developers who will pay big bucks to skirt some local busybody ordinance that says "no trailer homes".