Major typically writes these as much for his own notes / thoughts as anything. Having some insight into how he got where he is in the process can help some others learn. I’ve learned tons from the guy.
I’ve known him over 15 years, and he always has written posts for himself first. This isn’t a bad way, just maybe not the simplest for experienced folks. Laying out your own thoughts along the path can help later when you wonder why you did X instead of Y.