Okay... hold now, let's clarify what you mean by pure bred birds, so that there isn't some misinformation being put forth.
I like the thread idea, but I think
this idea that hatcheries don't sell purebreds is not correct in most/many cases (I'm sure there are some hatcheries out there that have some stock that are less that pure though).
Birds can be pure bred, but stray from the standard of perfection.
But your supposition seems to be that
because a bird does not closely match the SOP and/or does not match as closely as the best of the best stock of exhibition breeders, then anything less are not pure breds???
This is not true, it's just that hatcheries simply make no effort to cull in the same way that exhibitions breeders do.... and if they did they would likely not be profitable and would be out of business.
That is not to say that some hatcheries do have some polluted genetics in their breeding stock, and that backyard chicken keepers should be aware of this and purchase from the hatcheries that provide good quality birds, or purchase from an exhibition breeder if they are looking for something close to the SOP.
But this idea of: "Lets take and average bird and compare it to the best of the best, and poo-poo on commercial hatcheries and suggest that they all offer birds that are not purebred perpetuates a bit of a falsehood as far as what hatcheries are really about.
If anyone thinks that hatcheries are going to be producing or should produce the "best of the best" with in any breed, then that is likely just not in line with the reality of poultry production when comparing the two ends of the the spectrum: exhibition breeders and hatcheries.
Still it is nice to look at the pictures of the "best of the best" in each breed, such as this Leghorn pic taken from the book "The Magnificent Chicken: Portraits of the Fairest Fowl".... "Storey's Illustrated Guide to Poultry Breeds" also has some great pics of outstanding specimens.
But let's do so with the understanding of the truth of what we are comparing. Carry on... and my apologies for any distraction this posts creates.