Going back to the backyard chickens--during the Depression (when my mom was a little girl), my grandparents had chickens and a garden. Despite the fact that my grandfather was a pharmacist, times were tough--he often got paid in rag rugs, etc. If they hadn't had the garden and chickens, there would not have been food on the table every day.
Given that 1 out of 6 (or is it 5) families in the US cannot put food on the table every day, allowing people to raise hens is a good thing. Eggs are a great source of protein. I personally do not slaughter my hens (and, I do live in a city--however, I am zoned agricultural), in our area, a lot of people buy "ready-to-lay" hens in the spring and sell them in October. I got most of my original flock that way (buying the hens in October) and am the farm flock that way. Those girls are being integrated into my flock (I've lost some to "attrition"). I do have a friend who has offered to slaughter my girls, but I named them! I can't kill them.