They should have helped him. It will take a while but Rick will have to realise he's being too hard on newcomers. He might have already when he saw what Morgan was like.
I get the feeling that the backpacker needed to die to really drive home Rick's lesson. Had he passed and found him alive, his time with Morgan may well have given him a change of heart. As it was, I felt there was a glimmer of regret there in seeing the guy dead by the road.
It was a powerful bookend IMO. The desperation of the backpacker, the way he ran while pleading, and the opportunism of stopping to pick up the backpack afterwards were all fine touches.
The new show-runner is also the guy who wrote this episode and co-wrote the very good '18 Miles Out'. Hopefully we see more episodes of this ilk.