True, but also nobody cares about his book. This seems to be an article written for an American or western audience. A good writer would thus use a book or topic that Americans/Westerners would understand. We all understand Mein Kampf. We know who wrote it and that its not really hugely popular in the West. If he had picked a book about Ghandi, everyone in the West reading the article would understand the comparison, because we know Ghandi is famous pretty much everywhere. If Mein Kampf sold like...half as much as a pretty famous book either about or by Ghandi, we would all be like "oh hey, that IS a lot!" Instead he compared it to his book. I can't even find how many people in the U.S. bought his book. Apparently it was sort of terrible according to every review that wasn't on Amazon, so I dunno. I could see how it'd be a pretty terrible book judging by how the article was written. This was actually a super interesting topic that was made incredibly boring by a pretty mediocre writer.
I remember when I didn't think everything was a gigantic marketing scheme. Then you read about W&K and hit the weird realization that social media essentially functions as a means of cataloguing your interests to create cheap, personalized ad experiences. That life on the web has become a slow echo chamber of everything you already agree with is sent back to you. Everything else can be put on an ignore list. Not a giant conspiracy of course. Its just smart business. If the author was smart we wouldn't have even noticed. But he didn't and wasn't.