Though they all share some kinks--err, qualities, there are a few very different factors that influence each setting.

Aestivum continuity: Dragons were created as weapons in the last war, much as the Warforged serve this role in Eberron, though their creation is tied up in ancient magic. The dragons are new magic, but people are very wary. They need them too much by now to get rid of them all, but they're too afraid of them to let them off a short leash by freeing them and/or granting human rights.

Bodyshoppe: Dragons -- and all the other nonhumans -- are all biological constructs, many are neophiles, and many either started as or became kinky people, either seeking new ways to enjoy that, or learned from their experiences to enjoy the strange.

Everything that isn't one of these... is just my fevered imagination.