Dr. Garth Davis is an extremely well-regarded M.D who has featured on well known vegan documentary Forks Over Knives as well as many publicized debates on American television.
In this video, he responds to those who are ditching the vegan diet on their Youtube accounts.
He makes a great point in this video. Most of these YouTubers are just kids, some with very little experience in how to maintain and stay healthy on a vegan diet. The doc also makes a great point in saying, he advocates for veganism because of science, not because of what other people are doing. He does it for the environment, animals, health and all of the great reason you will hear in this video.