First, let me remind you that all domestic chickens share a common ancestry and descend from Jungle Fowl. All the breeds of chickens have happened because a human somewhere liked a specific trait or traits and bred birds until they consistently had those traits and type. Eventually, people, in order to maintain their breeds of birds, began to write down these SOP's so others would know what traits should be chosen for and what stock should be used to continue the birds to maintain consistent type and performance. As time went on, more and more breeds of chickens happened, because more and more people sought to make various improvements on those breeds that were already there. They used specimens from pre-existing breeds to create new breeds, new colors, more winter hardiness, heat tolerance, etc. etc. This is still going on today, in every country on earth, just about. Today, there are so many different breeds of chickens you would think there just would not be room for any more, but there are still new humans that still want different things! I think it has been stated before that the focus of most hatcheries catering to the public is different from the average show breeder. They have different goals. The show breeder seeks to breed a line that will produce show winning specimens. The hatchery seeks to mass produce a bird of recognizable type and performance that will survive the rigors of mass production and the US mail and survive your possibly novice care once it arrives at its destination. They are less concerned with the intricacies of conformation and feathering but do want to send a bird that looks and acts like the breed it is supposed to be. There are a lot of hatcheries out there and they compete with each other in various ways. Most need to make the majority of their customers happy in order to stay in business. The show breeder needs to make judges at shows happy (judges who hopefully have studied the SOP for that breed of bird and knows what to look for). Sometimes I think the whole "purebred" terminology should just be thrown out since breeding "pure" will not over time, necessarily produce a typey specimen unless a certain amount of care is taken to ensure that breeding stock used is capable of passing on the traits that the breed is known for. I think this is what you are probably meaning. Do breeders do a better job of breeding to the SOP? I sure hope they do since that is their goal and they are needed to do that to maintain important breed characteristics. Do hatcheries totally ignore the SOP? I don't think so, because then they would be sending you an unrecognizable bird that you would not be happy with and would be out of business. But they are unlikely to focus on it in the way that a show breeder will. You have to remember that they will never even see most of the birds they produce as grown adults. Anyway, if humanity were swept from the earth and chickens survived, it is quite possible that they would eventually revert to being various kinds of jungle fowl again, since mother nature would be in charge of their SOP and selection for traits based on survival would again be the rule.
... I've done business with them twice over the span of 20+ years, seems okay... but maybe they're they're one of the nefarious ones you're speaking of for all I know? I'd just like to have some specifics before I charge in there next spring and put that nice lady in head lock because the internet has convinced me she's out to get me! 
