Quartering shot

I watch a lot of hunting shows...almost all the time actually...and spend every evening reading AT and there is a lot of conversation about the "perfect" bow shot being a quartering away shot. I have been very fortunate in my bow hunting and have usually managed to take a deer during bow seasons. Most of my shots are pass throughs. A well-placed quartering away shot enters behind the shoulder (hopefully) and exits usually through the other shoulder, either directly or a bit in front. How is the hole that is left any different depending on which side the arrow enters? Isn't a pass through quartering away shot the same as a pass through quartering to shot? Why is one good and one bad?