The breeders breed what the judges pin. When the breeders focus exclusively on what the judges pin, they lose other important characteristics (especially working ability).
I used to breed Siamese cats, and we saw it there too. When the judges started rewarding the extreme, long headed, very fragile body type, the big breeders bred exclusively for that, to heck with temperament, health, etc.
That's why a couple of breakaway organizations are now breeding the "apple head" Siamese. My cats were never apple heads, but they weren't the extreme elongated type either. I took my best boy to Champion, but he would never have gotten any further than that, no matter how often I showed him. And the person who is in it seriously (I was just a hobby breeder) is going to breed what the judges like as quickly as they can.
I think you and I have had this discussion before. I'm going to leave it here, because, I like you, and we probably both have points (and I don't mean elongated heads). ;)
susie