I originally got them because my wife wanted them. She grew up in coal country and the farm lifestyle is a huge draw for her.
I could never get rid of them now because:
1 Therapy. I have a high stress job and I believe that sitting watching and interacting with them has kept my stress level down and me sane.
2 Bugs/yard care. My back yard has never looked better.  No dandelions, no clover, thick lush grass everywhere.  When we got them I had a tick problem in my butterfly bushes. Once the chickens found them the ticks did not stand a chance.  Every time they free ranged, straight to the butterfly bushes.  About a month later, no ticks to be found.  I had a grub problem, no longer.  They wiped the grubs right out.
3 Eggs. We are not in it for eggs but man, no other egg compares to fresh from the girls.  Just amazing.