Proper arrow flight means everything to a bowhunter. You don't want to have that sickening feeling of watching the buck you've worked so hard to get a shot at high-tail it out of the area after your arrow harmlessly whizzed by.
Many hunters stand in disbelief saying, "I don't understand how I missed," and the problem could have been prevented. They could be getting out their pocket knife to take care of business instead of reaching for their hanky to wipe their eyes.
Pay close attention to your arrow groups while practicing with your bow. If an arrow flies out of the group for no apparent reason, mark it and watch it carefully as you continue to shoot. If that arrow consistently flies out of the group change the point and try it again. As a matter of fact, it's a good idea to mark (numbers, letters, etc) all of your arrows for your reference.
Retire any arrow that continues to fly out of the group. There is probably something internally wrong with it that you can't see with your naked eye. It's better to throw away one arrow than your entire hunting season with a miss.