Love it! My personal sites tend to start hand-written, evolve into a bash script, occasionally advance into python, but mostly just stay in bash, because it's convenient, doesn't need to please anyone else (nor would it!), and is already built for text processing into files. (I write a lot of scrappy shell scripts for my job too. I guess I should start asking an AI to generate whatever I want directly instead. Cobbling together a script is more fun though...)

What is wrong with people.

The title seems to be a bit misleading IMHO because it does not really only use `sh` but heavily `sed` it seems, which is a whole programming language well suited for templating. I've in the old days written a Macromedia Dreamweaver compatible template engine using such a scheme, which I personally used quite a long time actually without Dreamweaver because this WordPress madness was even a thing.