Designer Pups

I have been around the dog world for quite awhile and I don't understand the big todo with the designer pups. No matter how you put it together they are still just mixed pups. The problem with the mixed pups, no one is considering the genetics. Real simple it's not just what you see you are going to get. I know a gal that is breeding Cocapoos. She is trying to breed them smaller and smaller. Her problem is on those very popular pups are their knee caps. They keep coming out of the socket which means they have trouble walking and then end up with surgeries. I'd say that is more than most people want. And she gets a pretty penny selling them. Worse of all she knows this could be a problem and she is selling those pups. People are calling her all the time.
Then there is the Labardoodle or the Goldendoodle. I know a few of these sweet dogs. I can't help, but wonder if the breeders (????) have taken the time to check out hips on their dogs before using them to breed. You know like OFA's on the parents. What I mean is if the parents have had their hips x-rayed to be sure they are not displace tic. I would bet not.
The long and short of it. If you like surprises than a mixed breed is great. But instead of supporting those questionable breeder's look at the shelters. And if you know what you want, look for a good breeder. One that will take time to talk. And not just interested in selling a dog.