Just so you know, I’ve volunteered to take on maintaining cgi/cgitb in my copious spare time (ho ho) since I started using it in a project shortly before this PEP appeared.
For the anecdotal evidence files, the target was an embedded Linux system that needed some http-based controls. Since this is a system with limited RAM and very limited disc space (more RAM), the usual big flexible server solutions were utterly inappropriate. We settled on thttpd since we’ve used it before for similar things. I quickly knocked together a Python script as a proof of concept and refined it into the final version fairly easily.
Had cgi not been in the standard library, we wouldn’t have used Python. Period. Bludgeoning the build system into acquiring PyPI packages is non-trivial, and frankly rather daunting compared with writing the equivalent script as a C program.