The best argument against free soloing is free soloing. Mortals don't usually get very far before it puts the fear of God in them. The one's who do are wired different, and are outliers even within the climbing community. Myself, I'm a bit stupider. I soloed several radio towers as a teen, and have done my share of questionable scrambling, but I didn't get very far at all with free soloing proper before I started to experience PTSD-like symptoms, and stopped.