I was inspired to write this article because two friends of mine have missed very nice whitetail bucks by aiming high. Also, when I went on my first elk hunt, the guide informed me that this is a common mistake made by hunters. My fellow hunter on that trip confirmed this by saying that he almost missed his first elk, when he aimed high and hit very close to his point of aim - and fortunately hit the elk's spine.
The fact is, a whitetail deer's kill zone is roughly the size of a supper plate, which means that "minute of whitetail" includes a reasonably large margin of error. Naturally, the kill zone on larger animals like elk provides an even larger area in which a hit will cleanly kill your game. Placing a bullet within that zone is easier than many hunters realize, as long as they master the art of accurately shooting their rifles.
Closer Than They Appear
The first misconception that contributes to this phenomenon is misjudging the distance to target. I will freely admit that I am not usually an accurate judge of distance based on my eyeballs alone. While on the elk hunt I mentioned above, I carried a range finder which I had borrowed from a friend. While hunting in any given place, I would check the range to various objects. I was surprised to find that many spots which looked to be out of range were easily within reach of my rifle - and if I had gotten a shot and aimed high, it would have been a big mistake.
Carrying a range finder can be a good idea, and I've since bought one of my own. A range finder can help you learn to better estimate distance by eyeball, and it can also add to your peace of mind. Once you understand how far your rifle can effectively reach (usually farther than most folks can or should shoot at game), you can easily range some objects around a stand or blind to determine a "kill radius." In other words, you can easily determine the limits of a circle inside of which anything you accurately fire upon will be effectively hit.
Flat Shootin' Guns
The other main reason why hunters aim high when they shouldn't is a lack of understanding of just how flat their rifles shoot. Most hunters are not ballistic experts (nor do they need to be), but a basic understanding of how a high-powered rifle delivers its bullets to a target can be useful. For a short discussion of how bullets travel in relation to your line of sight, check out this article: Why Will a Rifle Zeroed at 25 Yards Hit Close to Aim at Longer Range?.
I have been hunting deer for more than three decades now, and I've learned how to maximize opportunities. When I get a chance - and sometimes one has to act very quickly (but calmly) to transform an "encounter" into a "chance" - I want to make the most of it. And I have taken deer an many ranges, from right underneath my stand out to 230 yards.
I'll let you in on a little secret: I have never adjusted my point of aim based on the distance between me and the critter. And sure, I have missed deer in my life - but not very often, and never at long range.