Unfortunately, so often breeders would rather kill puppies that aren't what they consider 'good representatives' of the breed than spay/neuter and place them. I know the entire greyhound club was adamant until about 10 - 15 years ago NEVER to place retired racers nor sub-standard non-winning dogs. My old vet was one of the tireless workers in that cause.
Breeds that have the 'merle' coat (shelties, etc.) or black/white marked dogs like harlequin danes, dalmatians, etc. often wind up with at least one 'white' pup out of 5 when breeding merles to merles to obtain that prized coat. Routinely, the white/deaf pups have been "culled". For many years the AKC dalmatian club has recommended never placing the white pup because of "potential aggression" (because a deaf dog can startle easily, particularly if untrained).
This has only changed in the past few years.
Unfortunately, even the UK has become influenced by the American bad-breeding practices. It's unfortunate that the emphasis in that article is simply that if they do cull, that it must be humane. It's very sad to think that anything else is even thinkable.
From here I'll shut up ... I have a tough time with "breed standards" and breeding a dog for one particular physical characteristic or the absence of it.
I understand culling but it shouldn't mean death ... it should simply mean that pup isn't bred, but is spayed/neutered and placed as a pet instead.