I don't think it's fair to judge or condemn them based on the living conditions you see there.. it's a different culture so has different expectations and cultural "norms."
Plus, how many fish in your LFS are NOT kept in technically overcrowded conditions? I'm sure we've all visited plenty of LFS with overcrowded 10/20/30G tanks which we accept because we understand that they have the filtration to cope with the waste and the fish will not be in those conditions for long.
For the fish in that market to appear as healthy as they do, I'm sure they must have a massive turnover and stay in those tanks for only a very small amount of time. They probably spend less time in those tanks then the fish you buy from interstate vendors spend in bags during shipping, and thats without any filtration or water turnover at all..
Not having a go at anyone here, just asking that people keep it in perspective
-Dave