When you discover technical debt, the reason is always "historical grown". Here some anecdotes and reasons behind.
If you have other obscure, real, funny or anecdotal reasons feel free to submit the as a pull request or at the web form.
This site is live at https://historisch-gewachsen.de.
You can run historisch-gewachsen.de locally. It is written in Python and uses Flask. For the pre-made deploy-script gunicorn is used as webserver.
To run it on your computer, follow these steps:
git clone https://github.com/Varbin/historisch-gewachsen.de
cd historisch-gewachsen.de
./deploy.sh