First, the more effort put into developing & finishing a dog with titles takes a lot of resources, not the least of which is time, and a lot of folks don't consider breeding until they reach the goal. That loss of time can utterly ruin a bitch's chances of producing a litter, even if she is good quality.
This is an example of where I feel like we may or may not be missing a boat. In the horse world, dams aren't necessarily "required" to be titled (and I use that in quotes because I know there's no literal requirement) to be considered worthy of breeding. There are inspections, which I think is a wise way to do it - it's not the whole way to a performance record. I'd assume the WAE/WAC would be a good measure for Dobermans (or any other dog, modified for the breed of course).
Second, breeders who breed "too often" are usually savaged by other breeders and communities in the dog fancy, such as this forum, because scarcity seems to be viewed as some measure of quality. Artificial scarcity just means if the average person wants to get a Dobe, they'll either be ignored outright or stuck on waiting lists for years for a "quality" Dobe, or they can just go patronize the lower-end breeders.
Definitely an issue. I've seen this more than once. Keep in mind, rescue isn't always an option if someone doesn't have experience with dobermans or a tall fence. Many rescues will not allow you to have a doberman until you've had a doberman. I found this to be problematic when looking for my first. They may have reduced the stringency in recent years.
Third, up-and-coming breeders get savaged by other breeders and communities unless they play a particular game by apprenticing for a respected show breeder. Maybe that's a good idea for some who do need the guidance, but it isn't necessary, and being nasty towards those folks means that, if they even stay with the breed, they won't make the mistake of asking for guidance again.
This is upsetting and will end up killing the breed.
Fourth, popular sires are already influential enough, and most of the "good breeders" you're referring to don't stray far from the extremely popular bloodlines.
Fifth, there's a strong stigma attached to losing complete control over one's prized bloodline, such that breeders are savaged by other breeders if they allow their bloodline to travel outside of the clique.
Sixth, more breedings by fewer breeders, whether they're "BYBs" or "Reputables", aren't going to help the situation. Fewer, thoughtful breedings across a much larger population is what will ultimately improve health, temperament, and longevity. To hear your typical "Reputable" breeder talk, only one or two percent of dogs are worthy of being bred. The funny thing about eugenics is that it takes something that sounds good in theory, but whenever it's implemented strictly, it ALWAYS results in an unmitigated disaster due to the genetic bottleneck because the proponents always take it way too far. It doesn't matter if this principle is applied within the aristocracy, some concept of a "master race", or animals, sustained genetic bottlenecks invariably achieve the opposite of the intended effect.
Further food for thought: The typical "BYB" is probably actually helping aimless diversity in the breed moreso than "Reputable" breeders. I say "aimless", because genetic diversity alone isn't inherent quality, but it can be a measure of genetic resilience with a dramatically reduced chance of painting oneself into a corner of disease and misery.
This, and the two articles that Artemis linked, make total sense.
Ok, so if BYB actually provide a service (if aimless), perhaps then the aim should be to help the BYB learn about the dogs themselves, and what constitutes a quality animal. So, instead of condemning them, as we are wont to do, perhaps we should provide more educational resources. I'm just trying to come up with solutions. I think it's irrational for us to say that the BYB doesn't care about their dogs. The general BYB just isn't well educated enough to know what to breed and what not to breed. Millers are a different problem, generally related to care.
Very thought-provoking in general.