It's also used by certbot, pyjwt, ckan, proxy.py, scrapy, etc. The list is pretty long but I do agree with you that the majority of packages neither use nor should use it.
Glad you like it! Don't worry too much as we currently have a workaround. Their SDK still allows us to build kernel modules but the installation experience now requires manually switching the package post installation to allow root access .
This of course assumes that Synology doesn't remove this option before DSM 7 is released.
I've had a less than stellar experience with their support too. I'm the author of a reasonably popular WireGuard plugin (https://github.com/runfalk/synology-wireguard) and in the next DSM version they are basically breaking all kernel module plugins without a migration path. A kind user has found a workaround and made a PR, but Synology have no interest in helping out with this (https://github.com/runfalk/synology-wireguard/issues/66#issu...).
Shameless plug: If you want a static site generator with an admin UI I can recommend Lektor (https://www.getlektor.com/). You declare your data model and templates and Lektor serves an editing UI for you. There is a good video introduction by Armin Ronacher (original author) if you prefer to digest video content: https://www.youtube.com/watch?v=lTWTCwuPdrU
Disclaimer: Occasionally I moonlight as a maintainer of Lektor.
I've used buildah to set up a C/C++ dev environment in a Ubuntu toolbox at work without any major issues.