The only reason hunters don't aim for a headshot is because they lack the skill.
Shooting at the lungs is a pretty big target and a much easier shot. Your kill zone is the size of a basketball. Yawn.
A deer brain is about the size of a fist and they move their heads all over the place. That's a hard shot and much more of a challenge.
I compare it to a golfer's approach to a par 5. Can you make par by hitting 5 iron, 5 iron, 7 iron and a 2 putt? Sure. But pars are for pussies. Swing the big dog then nut a 4 iron to the green and give yourself an eagle putt. When you're in the clubhouse, nobody wants to hear about your boring ass par.
So yeah - hunting should be a challenge. And if you brain a deer - scream out "HEADSHOT!" from your tree stand to let all the other hunters you aren't some center-mass pussy.