There seems to be a disconnect here. What everybody keeps saying, and you keep ignoring, is that the simplest fact of the matter is that those people willing to become dragons permanently--and sure, there'd be plenty for all sorts of reasons--are not the kind of people those who can make them into dragons would be willing to use. Mainly because due to it being culturally viewed as an unwholesome and unnatural act, those who would do it are essentially willing to do unwholesome and unnatural things, which is not the sort of person you want to have such power. Sure, some people would do it for money, but why would you trust someone like that? Sure, some people don't mind being mutated and transformed for a large amount of power, but why would you trust someone like that? The only reasons it's even being done by us is because one: the transformation is not meant to be permanent, and two: the cultural differences makes it possible for us to find someone willing who doesn't believe it's inherently a bad thing.