I think there are several good reasons to order birds from a hatchery:
- You just want production layers, and get either White Leghorns (for white eggs) or a sex-link (for brown eggs.) Those birds are bred to produce, and if all you want is eggs, they do fine. I like the Golden Comets sold by Mt. Healthy, they are nicely tempered girls and they lay like crazy.
- You are just starting out in poultry and want to get a feel for what the different breeds look like/behave like. This I say with the caveats mentioned earlier that most hatchery birds will not meet the Standard very well for their respective breed, but they give you some idea anyway.
But if you really want to know what a given breed is like, order from a breeder. There are a number of big time breeders who sell a lot of different breeds of birds (Duane Urch comes to mind) from whom you can get better than hatchery quality (usually) birds.
And yes, you can occasionally get SQ birds from a hatchery, but I would venture to guess that's because at some point (sooner rather than later) the hatchery got their stock from breeders.
But I would never say that offspring from a hatchery would produce SQ birds. I won't even say that SQ birds will always produce SQ offspring. SQ is a very over-used term, what I like to say is (when selling birds for those who wish to show), is that the parents were SQ and the offspring are SQ potential.
But that's just me...