I fully embrace this. Definitely issues of that severity should be utmost on one's mind for all the reasons you stated.In defense of the NPIP testing for pullorum, in the 'good old days' it was an awful disease that has rightfully been tested for and pretty much eliminated.
Having a flock that isn't infected with either Marek's disease, or MG, or MS, or whatever, is wonderful, and with good luck and paranoid biosecurity it can be achieved.
Once infected, that's another story, and then you are trying to have a flock of 'normal' birds, and breeding away for 'clinically affected' individuals. It's that, or give up on chickens and do ducks. They are nice, by the way...
I want healthy birds who do what they are designed to do, who look like the breeds they represent, and never mind 'show quality' except if it means correct structure and production as meant.
My two forays into 'SQ' chicks did not work out; I'd rather have home bred birds, or hatchery birds instead.
Mary