It's not like anything he says is, by itself, that new or counterintuitive. But the whole talk, when fully digested, lets you view the world in an entirely different way.
The talk isn't about writing. It's not about science. Not about careers. It's about everything. The same thinking can be applied to speaking, to dating, to everything human.
What's in your head isn't intrinsically interesting to anyone except your mother. What value do you deliver? It's harsh. Harsh and cruel. It's not the cozy feel-good message you see everywhere nowadays. Maybe some would call the whole framing toxic. But would you rather taste the poison and then learn how to handle it, or would you stay ignorant and die of it (silently get ignored, nosedive your career, etc.).
In a masterfully meta way, the talk manages to deliver immense value.
He contrasted top-down with the bottom-up approach taught from elementary school to the undergraduate level which shows it as a superior approach to writing—if your goal is to introduce ideas that change the minds of your readers with your writing.