Why.. so you can re-write everything that is already written in Java.. .Net to be honest was a mistake. C# as a language is maybe more powerful than Java - but not by much. And you are forced to use visual studio to so anything productive.. Also can you mention 1 open source framework using .net/core NOT from Microsoft - that people in other companies actually use ?
Also whatever advantage C# has over Java is diminished by the fact that the JVM is simply amazing (.net has nothing like the JVM hotspot compilers). Also it has been battle tested by so many companies in so many different production environments and there are vastly so many profiling / debugging tools that it is many engineering man years ahead of .net. Unless an organization has serious investments in windows servers, there really is no reason to choose .net over Java. Heck - a lot of internal MS code is moving away from .net.
GitHub all Ruby on Rails , Yammer - Ruby on Rails , typescript/react and java , LinkedIn mostly java , there are some other teams that use java - like all Android teams, outlook mobile backend, hdinsight , some azure teams , some o365 big data teams
They’re so similar it’s confusing why anyone would prefer one or the other. I have preferred Java in the past, but that’s largely due to breadth of deployment options. In terms of language there is so much similarity there. Though I’m also assuming you’re directly comparing C# (and not some of the other .net atrocities) against Java.