I would rather say that the former group are wrappers around the latter group. Using an SSG doesn't just mean converting Markdown etc. source and orchestrating a build process of some sort, but also filling in templates and providing useful build steps to orchestrate (such as generating additional pages that reference the actual article content: archives, collections grouped by tags or categories, etc.). They also generally implement things like the live reloading that the author mentioned as missing.

I'm currently using Nikola and have done quite a bit of customization - by hacking around and learning modern web stuff as I go (the last time I did this stuff seriously, jQuery was dominant and Bootstrap was brand new - of course I'm not writing a bunch of JavaScript for a blog, but that also presumably dates my understanding of HTML and CSS). I've found that even though there's way more stuff in here than I really want, it's really nice to have that kind of scaffolding to start, and I can strip it away as I customize.