Some people in the Python community were recently looking into this very thing... and the results were surprising.

From https://talkpython.fm/episodes/show/243/python-on-windows-is...

"over 50% of all developers programming in Python do so on Windows."

Maybe the researcher is right, maybe they aren't. There is no solid way to tell. But there are a lot of developers out there in big, old school corporate environments. All running Windows.