Because Standard poodles aren't always that sturdy. Plus while they are smart and can learn the things they need to, retrievers just seem to do better at it.
And yes you are right in that not all the puppies will be non-shedding, but some will and those will be the puppies used to further the breeding program.

We groom 2 golden/poodle crosses. (I actually groomed one today in fact) and both resemble giant cocker/poodle crosses, no kidding. *yuck* Anyways, both have a non-shedding, easily matted type coat.