I have long thought that there's a big difference between breeder birds and hatchery birds. I think the wide variation in temperament is because the hatchery strains aren't really pure, and so if that's all you've had, you never know what the true personality of the pure breed really is.
Between my own experiences and what other people are telling me, I've just about decided I don't want hatchery birds anymore.
I've started looking for breeders to get my breeding stock from. Hatcheries are fine if you just want a "meat crop", or you just want some egg layers, etc. For any serious breeding experiments, or showing, or anything where you need good quality birds, I think you probably have to go to a breeder. Except maybe Sandhill, they're not really a hatchery, though, they're a preservation group.