Reasoning was given during Talking Dead. In a nutshell, in this world the other characters have no way of knowing if someone who went outside the gates is alive or dead and they wanted to give the feel to the audience.It's more the violation of the audience's trust to depict the death of a character with a full symphonic tribute during his death and to then bring him back several episodes later for no purpose other than to force us to reckon with his pedo-stache for another dozen or so episodes.
Done well or not I understand the reasoning, have accepted it and moved on. Per the rest of it I really don't see them taking many more liberties with survivors abilities/decisions than is found in the vast majority of zombie movies.