I have read every post in this thread, and in general, agree with most of the posts.
I can not adequately comment on buying hatchery chicks, or letting broody's do the incubating, hatching and raising of chicks.
Reason being I raise pheasants and quail.
Not many hatcheries have the rare pheasants that I raise, same for quail. Therefore, I have to relie on breeders or shipped eggs. I prefer to get eggs and hatch them myself in an incubator. Or if possible to pick up eggs from a breeder. I've been doing it for years and haven't once had a diseased chick hatch. Deformed yes, never diseased. There is risk in shipped eggs but there's also risk in buying hatchery, farm store, and breeder chicks. I have a very strict BIOSECURTY program. When raising gamebirds in particular, it is or should be priority #1. And I try to stress that in alot of the threads I post on because it seems alot of people don't understand or don't think it will happen to them, and skip over the importance of biosecurity, until their asking for help on here for a sick bird.
Another reason for buying shipping eggs is,
most pheasants and quail do not go broody. I have had a few pheasants that did but they couldn't raise them...once they hatched, the hen ignored them, or the cock bird killed them. They would also stop setting half way through...the motherly instincts have been virtually bred out of pheasants. This is the reason I incubate.
Brooding pheasants and quail is completely different than brooding chickens. Pheasants and quail are more prone to overcrowding, takes more room to do so than chickens. Also, some species of pheasant chicks can not be raised together with other species of pheasants, like chickens are...they will kill other chicks not of their species. Most have different habitat and nutritional requirements than chickens. And unlike chickens, pheasants and quail can not be "free ranged". Most of the birds I have raised have become tame, eat out of my hand, if I sit down in the pen, they will walk and climb all over me, so I think they don't need a hen to teach them how to behave as a pheasant, or how to find food, or escape a predator. A few of them haven't had that bred out of them, yet!
I raised chickens 50 plus years ago, show birds. Back then I did the same thing I do today, I incubated my eggs, because of the breeding program I had for my show birds. I occasionally got other birds from breeders that were in my circle of breeders/ showers, for new blood. I knew the quality of the birds and reputation of the breeders, I never had a problem with a diseased bird back then either.
In conclusion, there are some good hatcheries, breeders and then there are the not so much ones, too! It all boils down to what a person thinks what's right for them. How and what they want from their chickens, their experience level, location and financial situation as to whether they go hatchery, farm store, breeder, incubation or the natural way to obtain their goal.