People Habitat: 25 Ways to Think About Greener, Healthier Cities by F. Kaid Benfield (2014)
One thing that none of the pushers for multi-family dwellings ever address involves NEIGHBORS. Single-family dwellings are desirable over anything else — not because people have no interest in environmental impact — but because dealing with other people can be a nightmare. Thin walls are not funny in reality. Even single homes can have issues: Good fences make good neighbors!
Unless some law or soundproofing regulations or roving enforcers with martial arts skills are part of every multi-family dwelling, the problems of conflicts between people will still drive people who can afford it to buy single-family homes. Plus they are going to want big lots so there is distance between them and still noisy neighbors.