Which hatcheries did you find them at? I find some listed at Ideal and McMurray.I only found two hatcheries that sell any variety of Cornish, and both of them had nearly non-existent availability for chicks. I only saw Dark and White Laced Red Cornish.
Ideal Poultry had three colors a few years back (Dark, Buff and White Laced Red), but I only see the Darks now.
McMurray Hatchery lists both Dark Cornish and White Laced Red Cornish.
Many hatcheries quit selling chicks during the fall and winter months, but they are usually available again in the spring and early summer. It looks like Ideal and McMurray are both following that pattern. If you want to be sure of getting chicks from either place, watch the websites in December or January, to see when they start taking orders for the year. Then place an oder and pick a ship date that works for you, even if the ship date is months in the future at that point.
Probably not the reason. If someone wants to re-create the commercial Cornish Cross, they can save a few decades by starting with existing Cornish Cross, rather than starting over with purebred Cornish and Rocks and maybe other breeds.These birds are a major component in the trademarked and hidden lines of the commercial broilers. I believe this is why many people are not breeding them. I think that the hobby farm and homesteaders don't want to be seen as "competing" with the major producers of Cornish Cross. Perhaps they have been sued. I don't know.
The current Cornish Cross breeding stock are very different than the heritage breeds that are their distant ancestors ("distant" being less than a century ago, but there have been enormous changes in that time.)
I think they are not being sold because not enough people buy them. Not many people buy them because they are not efficient egg layers, or meat producers. They don't lay eggs of unusual colors (blue or green). They don't have odd feathers (Silkied, frizzled, crested, feathered feet, etc.) They don't lots of fluffy feathers. They aren't a currently-exciting fad in color or breed.
So basically, of the things that will make people seek out a breed and buy it, the Cornish are pretty lacking across the board.
(Personally I like them: pea combs, not extra feathers to get in the way, attractive colors, nice solid build, brown eggs. But I realized a long time ago that my preferences don't match what most other people are buying.)
It's the same as sexing a chicken with any other kind of comb: the combs on males will get big and red sooner than the combs on females do. But the differences are most obvious on single combs, less obvious on pea combs or pretty much any other type of comb. So that makes pea-comb chickens a bit harder to sex.I'll have to look up "pea comb sexing" as I've never heard of such a method.