While I confirm that writing is a powerful medium for thinking, anybody writer with a shower to take or a hike to walk will tell you that thinking takes place in many ways.
Parts like "If you want to learn and remember something long-term, you have to write it down" depends so much of context. Again, writing down does help me to commit things in memory, but for some information, audio is better. For others, repeating in my head is better.
Good advice all in all, but the definitive tone of the article is not needed IMO.