Part of the problem stemmed from the fact that a lot of PMU farms in north america were labelling their draft crosses as American Warmbloods-and consequently, a lot of people bought these horses, expecting them to be registered with the AWR.
(because by the truest sense of the word, a warmblood is a mix of a coldblood and a hotblooded horse...which is what the PMU horses were. But obviously in today's world, the term warmblood means something entirely different)
Now, I believe that the AWS can register and approve draft horses. Some people seem to believe that that means that every little nag can be registered by them. But if they are run even remotely close to any other breed registry, I would imagine that they are quite strict in their judging. They just happen to believe that an influx of breeds other then warmbloods and thoroughbreds are needed to create a better horse.