That sounds like an extremely narrow use case, compared to what the vast majority of Sheets users will be comfortable with

At the same time, it makes some sense... the programmers for a system aren't always the best users of a system. So if you're expecting them to dogfood their own system (Google Sheets), you might find that they test/interact with the system primarily through the API and not the GUI.

I have no idea if they do or not, but it's a plausible explanation...

Use case feels like the wrong term.

Do you mean restricted workflow? Googles APIs are pretty much 1:1 to the GUI

And using Python makes it trivial to copy-paste out of files and other APIs with one run of Python

Versus all the fiddling in browser tabs with a mouse, it actually affords an incredibly wide set of options to quickly collate and format data