They did, hence Boo

https://en.wikipedia.org/wiki/Boo_(programming_language)

I would argue that C# has always been a good alternative for games, starting with Arena Wars, the problem was Microsoft not being serious about AOT or low level programming, because that was left for C++/CLI.

https://en.wikipedia.org/wiki/Arena_Wars

Here is the person responsible for pushing XNA, even though management wasn't into it.

"The billion dollar decision that launched XNA"

https://youtu.be/wJY8RhPHmUQ?si=_3pic4pEiOlqQzvm

When she left Microsoft, XNA was promptly replaced by DirectXTK, because C++ is the only true way for DirectX team,

https://walbourn.github.io/directxtk/