The problem is that commercial hatcheries don't care if their hens suffer and die from egg peritonitis/salpingitis--they cull them at about 2 years old anyway. I've watched too many wither and die from reproductive issues to want to see that again if I can help it. If they are just considered egg machines, pushing them would be fine. Then when the machine breaks from overuse, you replace it. They don't just run out of eggs, they die in pain when their bodies cannot keep up. I'm just not able to think of them that way. My poor hatchery girls didn't even stop to molt for the first two years, poor things. I even wished I could get some of them to quit laying so they'd grow their feathers back and get a little rest.