I truly believe that it has to do with people not practicing enough during the off season with hunting clothes, from treestands, and with broadheads.

I also think a factor is people overestimate their maximum effective ranges on live animals. I'm a pretty good shot according to most people I've shot with. I can shoot 3" groups at 60 yards in the yard. However, I almost lost a nice buck this year because I chose to stretch my maximum range a little bit (he was 35 yards). Luckily I got him (the one in my avatar) but I vowed never again to shoot anything over 30 yards and preferably 25 yds or less. I've double lunged all 4 deer that were less than 20 yards. The first time I took a 35 yard shot I had to track it for 2 days! Never again....