"Have you ever put a wood arrow tight behind the shoulder and NOT gotten the penetration you needed? Ever been on a back country hunt in foul weather and warped shafts? Ever slip on a rock and break some shafts in your quiver?"
No, no, and no.
I'm sure there are times that wood arrows have failed, but with the exception of breaking several while stumping, I have never had a problem. I have had a few that did not listen to directions and missed what I was shooting at; just last week, my arrow failed to hit a big color phase black bear. It couldn't have been me, I was only 10 yards from the bruin, so it must have been a contrary arrow.