Happy endings are rare in the world we all live in. I don't expect them to be abundant in a world where the dead have risen to chomp on the flesh of the living.
Anyways, I don't think we've got the creds to be giving TTG storyline writing advice.
The guy who wrote these episodes is a professional. Wrote Book of Eli and prolly some other stuff. Pretty sure he's more qualified than any armchair critic.