A guy doesn't have to be a world class shot to take game, but he does have to recognize his limitations. If when shooting off hand, hitting an 8" target on demand is what you can do at 100 yards, and you know that when you see a game animal at 200 yards without being afforded the opportunity to shoot from a rested position, you have to get closer, you are on the right track. Knowing what you can do on demand and under what conditions you can do it is the key. For most of us the adage, "If you can get closer, then get closer and if you can get lower, then get lower!" applies. It does make you wonder why a guy needs a rifle with 5" of drop at 500 yards.
What bugs me is that guys are out in the field with no concept of range to a target, trajectory or time of flight of their bullet, effect of light and wind, the affect of the angle of departure, or even how to assume a correct shooting position, let alone the basics of marksmanship. Add to this a game animal that is moving and it's not going to be a happy ending.