This list really just lists the sheer amount of homes, but really, any location could be desirable for a 2nd home. All about personal taste. Some prefer the plains of Montana, others prefer the Victorian Homes of Detroit. I don't see it as a reason for one region being the epitome of luxury versus another.
Although it would be nice if Detroit could fix its crime problem. Prices are so cheap. I can buy a 10,000 square foot home, old Victorian, for cheap. Probably less than 400k. IDK what I would do with all of that room, but I would figure something out. One room could have a statue of me, the other, a statue of my pet, and the other a statue of anybody who will pay a donation. A house full of statues.
Something like this would be nice:
http://detroit.curbed.com/archives/2...asks-300-k.php
Such a nice stock of Victorians in this city.