I've seen this being said on TWD boards and I tend to agree. All life is precious is a great code to live by and I agree it is. However, it is much easier to live by when you're in an isolated cabin out in the middle of nowhere by yourself. When you're out trying to survive around hundreds of people trying to kill you every other day it just doesn't cut it anymore.
"All life is precious." and "Sometimes people need to die." aren't necessarily mutually exclusive to me...especially in a post-zombie apocalypse scenario. In fact it is the former idea that should temper the latter.