Nowhere did this person advocate screaming at someone for doing something stupid. There is a huge difference between screaming at someone and saying calmly, "Hey, what you're doing right now isn't cool. You're just hurting yourself/someone else. As your friend, I don't like to see this. I think you need to listen to your therapist/mother/whoever is giving you good advice, even if it's hard to hear."

Putting a band-aid on it and agreeing with them when they're being deliberately stubborn, dense, or just plain wrong is not helping them in any way. You're not helping them to calm down. You're helping them to delude themselves. I.e. you are not being a friend.