The thread you are referring to, initially it sounds like your cousin is an inexperienced person, and would be what is known as a "back yard breeder." Otherwise, she'd already have done plenty of research, and known things like what her dog should be certified for, and how much a pup should sell for. So it is no wonder that people responded as they did.

That's not "nagging," that is people trying to discourage uneducated breeding, because of the number of dogs put to sleep for lack of homes every year.