It's so interesting to me how people consider writing bash scripts to be some sort of absurdist gimmick. I've made some scripts like this for blogging, as well as many other things.
It's often not the best choice. There are situations where, I'd argue, it is. One of the main reasons, in my experience, is for very lightweight servers. I don't want python or node or anything. I want to run a web server with 128mb of ram and a 1gb disk. Somewhat niche, but it's useful to just use the base system.
The other useful thing about it is knowing your shell in general. Even if you're not on the infrastructure team, being comfortable knowing how to navigate a system is both fun and sometimes critical. You never know when you'll need it, and it's an interesting look into your tools.
It's akin to saying "why know how to use a saw when you can use a chainsaw" or "why know how to make a fire when you can use lighter fluid and a lighter?" Sometimes things come up. And it's fun to know how we got to where we are today.
Its very niche. This is a static site generator so you could run something a lot heavier and then rsync the output to the server. Even lighter on the server than running bash there.
It is also limited so you might have to add other things. The README suggests using markdown.pl for markdown support.
Bash gets way more hate than it deserves, in ways that are like "this kitchen knife is terrible for cutting down trees!"
Like, yeah, why are you mad? And also, if a dude wants to cut down a tree with a kitchen knife that's actually pretty impressive.