If you want to get someone driven to shoot better, just show them how the gun shoots that you sighted in and let them shoot it (poorly). I zeroed a buddy's 350 Legend in a few weeks ago. It shot .75 MOA for me out to 250 yards. When he shot it, he shot it high and left but about 3-4 MOA. I kept telling him he's picking his head up off the scope immediately after he pulls the trigger. He was so mad that he couldn't group that he just wanted to sell it. He doesn't shoot much but he called me a week later asking if we could go back out so he could shoot some more. Time behind the rifle you hunt with is actually the most important thing. It's what ables perfect shot placement. No substitutes.
They don't follow through with their shots. This is where dry firing comes in to play. You can literally catch yourself jerking the trigger, flinching, lifting your head or moving it to the side to see impacts, etc.
Many shooters and hunters don't know better, and dry firing teaches "Follow Through". Many think this only applies to shooting moving targets but it applies to all shooting.