I guess you have to figure out where you draw your own lines. I wouldn't buy from somebody who used a double-merle in their breeding program because I find the practice of double-merle breeding disgusting. And I just cannot fathom that there could only be one dog in the world who would fulfill their breeding needs.
But those are my own personal lines in the sand; they don't need to be everybody's. I feel strongly on the subject. I feel less strongly on other subjects.