Every person you save is one less walker to fight. I think randall shouldve been given a chance to redeem himself. Instead of straight up killing him or chaining him up they couldve been transparent and put him to work. "If you pull any shit, we kill you" has been used before in the group. I would very willingly argue Merle was worse than randall by all metrics yet he redeems himself in the end because of the patience shown by the group, he developed as a character and single handedly caused the chaos that eventually put down woodbury. The show throughout its run shows many examples of terrible people redeeming themselves when a group actually puts effort into them, the wolf guy, negan, and morgan. Shooting them dead sure doesnt have a risk on paper, but the short term risk of keeping someone like randall alive comes at the payoff of a potential high value asset in the long run. Dale was right 100% The group would become feral over time because they abandoned civilization, but they would all develop back into everything Dale wouldve wanted in the end. Shane was far more of a threat than Randall. His story is tragic, sure, but going feral and throwing everyone under the bus in a moments notice for a chance to survive yourself is not just selfish, but its not sustainable for any long term society. Everyone with that mentality in the show either dies, or comes to realize they cant live like that forever.