I'm not sure this is the person we should listen to on engineering management. This quote is a huge red flag to me:
"I advise developers, anytime they’re looking at job ads, serious developer positions, not front end developers..."
How can he retain great front end engineers if he doesn't even think it's a "serious" position? I've done machine learning, kernel hacking, back end, mobile, and front end, and it takes just as long to learn to be amazing at front end as it does to learn any of the other categories.