My answer to this question isn't the same now as it would have been a couple years ago. I started out buying hatchery chicks simply because I wanted a backyard flock to "lay eggs and look at" and it was much easier to justify the cost of hatchery chicks. The problem I ran into, though, is that although a lot of the hatchery birds were perfectly healthy and pretty, the sometimes drastic variations from the breed standards really bothered me. I also realized that if I wanted to play around with genetics and breeding as a hobby, I wasn't giving myself much to work with and it would be irresponsible of me to sell my birds under the breed name they were sold to me (since even as an amateur chicken enthusiast I could see they were poor representations). So far I've decided to try to build up my flock via hatching eggs shipped from breeders but I am seriously considering ordering chicks from a breeder next Spring.
Another thing that would bother me about buying chicks from a hatchery, even one offering a specific line, is that unless the hatchery bought the breeding birds directly from the breeder they mentioned and the breeder confirms it to the buyer, there is a chance that the hatchery could either knowingly or unknowingly be passing off birds that aren't from that line at all or are mixed with other lines. It is something I have learned from the Marans Thread in the Breeds, Genetics and Showing section here on BYC, by going to different respectable Marans Breeder websites, and by perusing ads from local chicken breeders and Ebay auctions. With the Marans in particular, you get all sorts of people claiming to have "pure Wade Jeane lines" but in reality they obtained their birds second hand from another breeder who claimed the same thing and so on and so forth...so that they only way to be sure you are getting the real thing is to buy your own birds directly from the breeder.
Another thing that would bother me about buying chicks from a hatchery, even one offering a specific line, is that unless the hatchery bought the breeding birds directly from the breeder they mentioned and the breeder confirms it to the buyer, there is a chance that the hatchery could either knowingly or unknowingly be passing off birds that aren't from that line at all or are mixed with other lines. It is something I have learned from the Marans Thread in the Breeds, Genetics and Showing section here on BYC, by going to different respectable Marans Breeder websites, and by perusing ads from local chicken breeders and Ebay auctions. With the Marans in particular, you get all sorts of people claiming to have "pure Wade Jeane lines" but in reality they obtained their birds second hand from another breeder who claimed the same thing and so on and so forth...so that they only way to be sure you are getting the real thing is to buy your own birds directly from the breeder.