why can't wolverine heal
In order to make a different Logan, and a different tone of a Wolverine movie, we felt like we couldn't hold on to every tradition established in all the movies religiously, or we'd be trapped by the decisions made before us. So we questioned whether Logan's healing factor causes him to heal without even a scar. We imagined that it may have when he was younger, but with age, he's getting older and ailing. Perhaps his healing factor no longer produces baby-soft skin. So we imagined he heals quickly, still, but it leaves a scar.