All truth passes through three stages, first its ridiculed, second it's violently opposed, third it's taken as self evident. Arthur Schopenhauer wrote that and later on Mahatma Gandhi used it.
David mentions in this useful interview that quite possibly nobody has ever been more ridiculed in public life and it's for that reason alone it's worth taking the time to listen to a more laid back discussion of his life and experiences here.
If there's one trait that is hard to deny with David it's his authenticity. It's worthwhile getting to know what he is about and what he stands for before making the mistake of following the knee jerk response that comes from following the herd. I'll say one thing that I sense about David and have observed on occasions, which makes me a little sad. Every time a new person approaches him for whatever reason he has to adopt a defensive manner that means he doesn't reject people without reason, but that he can't allow many people to get too close to him as many must have tried to gain his trust before betraying him for a cheap laugh.
Outside of his family I feel his job has been one of the loneliest in the world. That's worth hearing a man out on, and one day if I find the inspiration I'll try and find a new way to explain his most explosive information as he's not sharing it because he's delusional, or because he's daft or for a quick buck. He could have had a long comfy career in TV if he wished and few have walked away from popularity into ridicule so purposefully. Few if any at all in history or am I wrong?