There are many more Rails developers out there, but there are also a lot of hacks in the community. There are probably close to as many good Django developers as there are good Rails developers - you just don't have to hunt through the bad ones as much to find them.
Sorry, what? How could one possibly know there are more hacks in the Rails community than in the Django community?
I'm all for comparing the merits of various languages and frameworks, but this article is more about gut feelings than facts.