IMHO,When you start shooting at whitetails over 40 yards all the confidence and shooting ability in the world isn't going to keep a deer from ducking or spinning on a shot. A deer on high alert can duck an arrow from a high speed bow atless than 20 yards. But at these shorter distances you can compensate by aiming low with the anticipation the deer may drop into the shot. At longer distances this margin of error increases beyond the point of anticipation. Even a calm deer at 50 yards can react to a shot and totally spin or duck that could result in a poor hit. Im not saying you can't make a good hit at these distances it's just the margin of error is beyond any hunters effective killing ability due to the deers unpredictable nature.
Out west it is a little different...The size of the animals are in most cases much larger which decreases the margin of error making longer shots more effective. This is just my opinion.