What is this trying to say about writing?

It's saying that if someone thinks that the act of writing is just about following a protocol on how to write, this someone is wrong (the misconception statement). Then it states why everyone who has to write essays should outline them first, not outline them after having polished the final draft. It emphasizes the importance of outlining prior to writing the actual essay using, as an example, the way our parents were taught just the opposite and what that got them into- jobs where they didn't have to think, just follow the rules. That, in turn, made people of those times view writing as too sophisticated for them to understand beyond spoken language instead of an art that it actually is. It's like saying "plan your actions, then act" or "think before you act."