I don't breed my own feeder mice (my snakes eat small mice and fuzzies...I haven't bought a pinkie in years), but I do purchase them from a very small, private organization that does reptile awareness, rescue, and education and breeds (and kills) their own mice. Obviously I don't have a veterinarian checking these guys out, but I see how they are kept and there is no sign they are unwell, and if I found out these people were knowingly sending me rodents with infections and unknown viruses/symptoms, I would be VERY upset.
I just don't see the logical behind that at all. You wouldn't see someone post about their chickens who are packed into a tiny, dirty enclosure, unhealthy, being fed unsafe hormones and cyanide, and suggest that since that person can't handle them, they sell them as people food, and say "oh, large meat farms do it anyway so that makes it ok."