I am not a breeder but I am a Yorkie owner.
There are certain things I look for in a "breeder".
The way I look at it is this.
There are good breeders and there are not good breeders (mills, backyard...).
"Breeders" are the ones who will do health screening on their dogs, sell them at the right time, not breed more than two or three kinds of dogs, have sanitary living conditions for the animals (and I prefer this is in the breeder's house, not a kennel), provide at least a one year health guarantee, reserve the right of first refusal if the pup needs to be rehomed... The part that does get fuzzy with even good breeders is how much testing should be done. I prefer that the pup is more expensive and more tests are run on the parents then selling a cheap Yorkie who has a bigger chance of being diseased.
As long as you are doing your research and planning to health screen and put the money into it AND your dogs are standard with healthy lines, I don't think there is any reason someone should tell you not to breed. After all, if you reserve the right of first refusal your pups will never contribute to the number of homeless pets. They will always have a home with you if they need one.
Puppy mills and backyard breeders are the opposite of what I'd call a breeder.
The dogs live in unsanitary conditions.
They aren't health screened.
The pups are sold way too young.
You can take the pup to the pound if you get tired of it.
They don't care about bettering the breed.
That is my two cents.
