Earlier quoted context omitted.
Please don't do this here.
Dang, I am not sure he is wrong. His comment is snarky, but there are reasons to think that the explosion of social networks has led to a major mental health crisis, especially among the young, and it may indeed be true that social networks are optimized to make you angry, depressed and resentful.
Your longer explanation would have been fine as the GP, for example, but the GP comment wasn't anything like that.