>The idea of purebred dogs is a fairly recent concept and a pretty terrible one.

It's just that the inbred traits are so desirable. I've had many mutts, and loved them very much. But when you want a dog, and you want to know exactly what you're getting, it's hard to beat a pure bred. Yes they will have problems, but it's a known quantity. And what you get in return is a dog who needs minimal training to behave exactly as you wish.