I didn't say anything about easy or hard (again you are injecting). Yes kernel programming is hard. However it is not "impossible" :

case in point-> The Elements of Computing Systems: Building a Modern Computer from First Principles (by Noam Nisan).

Your average CS student can do this (from nand to tetris). Kernel development is hard (without a doubt), but not impossible.

"The important stuff gets done by truly outstanding people. To deny this is nothing but laughable."

Once again, you are adding things that do not exist in the original article.