"Photos of wounds, deer on the ground, accounts, ect ect, none of that was good enough, he wanted detailed photos of wound cavities and shredded organs to be convinced."
Actually that's not what he asked. This was his statement:
"...but the more a person using a black powder rifle can learn from seeing the damage done by a properly placed shot from a round ball the more confidence a new user of a muzzle loader hunter would have."
I took this as people such as myself who were first interested, but, like many, know more about modern firearms, and as you mentioned the modern muzzleloader guys try to convince potential customers they need the newfangled stuff.