There may be those in the hunting party that would shoot and kill Old Ben if they got the chance... General Compson, for one. However, most of the men and the one boy, Ike, who go out hunting year after year, are more part of a pilgrimage than a true hunting parting. They all gather for the quest more than the prize, the camaraderie more than the pelt, the sharing of stories, more than the confrontation.
And more than anything, they just want to be in the wilderness, in the realm of the legend, in the primal woods where we all have our ancient roots. For most of them, killing Old Ben would mark the end of their belief in the already dwindling wilderness that has given them so much. No doubt if it came down to it, and any one of them were face to face with the massive, towering bear, none would ultimately have the heart to shoot and kill what has meant so much to them for so long.