I think you've just had crappy luck so far. I got shipped Serama eggs from Florida to WV. She sent me 19 eggs, 2 never developed, and one bloodring early. The other 16 made it to lockdown and only 5 didn't hatch! And we're talking tiny seramas with a lethal gene! Packing was excellent, and the post office was kind. (omg, did I just type that? lol)
My point being that maybe your location or the routes coming to you have just been bad. Or you've had less-than-stellar shippers?
I've had crappy results from shipped eggs also, but I keep trying because sometimes we do get lucky!