I guess it all depends on what you consider a BYB to be. It's not a clearly defined label and opinions of what a BYB is by definition obviously differ. I personally don't a BYB is defined as simply anyone breeding who does not show their dogs. There are people who breed that have very noble intentions and the best interest of the dogs and breed in general as their primary concern that do not show.
As far as buying from a broker, well, that's another story altogether...
I can't for the life of me justify it or understand why anyone would support that kind of business, nor can I understand why any breeder supposedly not out just to make a quick buck would turn over their dogs to one. (IMO, no respectable breeder ever would!)