You are confusing devkit, which uses vs license, with base C# extension which is free.

Also

https://news.ycombinator.com/item?id=41884187

https://news.ycombinator.com/item?id=41809351

https://news.ycombinator.com/item?id=41639205

https://news.ycombinator.com/item?id=41384888