Hobby/Conservation of the species. People do eat them when hunted in the wild (and the populations are VERY low), but I would say anyone who would eat them in captivity would be crazy --- Pairs go for $250-$450 each and eggs can sell for $30 an egg.
I've seen people describe these birds as an artist who took a piece off of every single quail, and composed them all into just one quail.
Like I said, I haven't had them too long, but am really enjoying them so far. It took me months to even be able to find any for sale.