“So what do people think of the crossing of two different breeds if both parents have had all the health tests that we expect a breeder of purebred puppies to do?”
It’s better than nothing, but...There’s a few issues that still doesn’t resolve.
Firstly with a good breeder of pedigrees, they know the breed, the lines and the conformation if that breed well enough that they aren’t using dogs with other health issues that aren’t tested for, like skin allergies or digestive issues - that’s less likely with two breeds. And that their physical traits complement or improve on what you have, so you’re not creating an issue like luxating patella which is essentially a confirmation issue.
You’ve also got the issue of what it is that people want from a pet that making its behavioural traits less predictable solves, because that’s what crossing breeds does...
Take lurchers, I’m originally from the middle of nowhere, where people do breed lurchers to “work”
So they’re mostly greyhound, sometimes with some deerhound in there and every few generations they add in something bully for stamina and some collie for intelligence, they’re breeding with purpose, they know exactly what they want and have lots of experience at it... and what you get is the odd puppy that came out how they wanted and a whole load that will never be capable of the job they wanted them for.
So if they with generations of experience, tried and tested methods and knowing exactly what traits they’re hoping to get can’t predict it, what is it maltipoos or other random cross breeders are thinking they’re going to manage to get... and how is an unpredictable cross better than the original breed?
There’s also the ethics of it, of using your dog to make money, pregnancy, birth and raising a litter takes a huge toll on a bitch and to do that to them for profit I don’t think is ok (I appreciate that other people aren’t as bothered by that, if everything else is done ok, but I don’t think money is the right reason to be breeding)
So in general, I don’t thinking deliberate crosses aimed at the pet market are a good thing.
The best chance you have of buying a pet dog that will suit your home and lifestyle and that you’re not also giving your money to someone exploiting dogs is either to buy a puppy from a breeder who is doing it all right and for the right reasons, or an adult rescue dog.
Anything else is a gamble, how much of one depends on where the dog has actually been acquired from, but still a gamble.