As I say in a sister thread, I transitioned from handmade websites to blogs as the author describes, and then from blogs to social media. The reason was also what the author describes: convenience.
I am the same person. I don't think I was more of a nerd when I wrote personal websites in 1998 than when I wrote blogs in 2002 or social media posts later. So I do think the tools have a lot to do with the changes described in the post.
It is true that non-chronological CMSs exist today, and they may be formidable in many respects, but I don't think they're better than MT in terms of ease of use. And also, the competition has gotten easier and easier: MT was just the beginning, now the real "trap" (as the author of the post would describe it) is social networks. The site generators you mention don't remotely compete in ease of use with social networks.
The only attempt I have seen of making publication of "permanent", non-timestamped content as easy as that of chronological content was Opera Unite. It didn't last for long.
Obviously the title and text are hyperbolic (personal websites still exist, there are just fewer of them) but the gist of what it says rings true to me, and I'm not an Eternal September curmudgeon.