Your breeder friend is absolutely right. Sorry, but who in their right mind would have two puppies when they work full-time - which presumably means being out of the house for at least 8 hours? How do they get toilet-trained, feed properly, etc., etc. Even if you have someone coming in during the day, you, as the owner, are missing out on crucial training and bonding with the pups.
My guess is that the would-be owner thought that having two dogs would be company for each other when left for a long time. This is true to an extent with older dogs, but does not work for puppies. The mind boggles as to the damage that could be done by two pups left alone for that period of time, and the damage done to them by leaving them for that amount of time.