"I could buy a Windows PC, buy some Microsoft development tools, learn how to use them, create something to run on a Windows Pi, then read through the huge license agreements to see if I can distribute the result, and hope that Microsoft's tools will still be maintained at an reasonable fee in five years time"
Have you tried this lately?
Buying a PC? No problem.
Buying the MS dev tools? No. You rent them, except in certain very limited circumstances.
Licencing? Good place to start, there's a 30+ page brochure (1MB PDF!) on how to licence Studio and what you can and cannot do with it:
"The buyers get to make their own choices."
Now we're talking. But you have to move off MS to make that happen.
And my choice, even where the Certfied Microsoft Dependent IT Department insist on Windows, is usually gcc and Eclipse; maybe clang/llvm one day. But then I mostly (but not exclusively) develop for embedded systems not desktop apps. And that particular IT Department wouldn't know a non-MS application if it hit them on the head.