In many of my conversations with breeders, removing the dew claws had nothing to do with showing, period…. sure it is one less nail to trim... but it really had more to do with seeing the damage that can be done... granted on our breed, you can see the dew claws and can see when they need to be trimmed, but I have seen way to many long haired dogs that people never bother with them... only to have them grow back into the leg from never being trimmed. Heck... think about how many people don't do nails at all, let alone worry about the dew claws.
And I agree with lvoss... it is not just dew claws, it is how it relates to the rest of health testing, Fanconi, eyes, hips, elbows, thyroid, etc... contracts, spay/neuter, taking dogs back, DNA for parentage, AKC registration (in the US)....
Things like dew claws "alone" can be debated until the cows come home... same as circumcisions, but the point was how it relates to what else the breeder does to be responsible