May be people will pick up C# for non windows projects in the future, but the past just wasn't favorable for it. The first version of C# was a 'meh' - Microsof

May be people will pick up C# for non windows projects in the future, but the past just wasn't favorable for it. The first version of C# was a 'meh' - Microsoft's Java(I already know Java; why bother?). C# got interesting(and a better Java IMO), but it took time. C# didn't have package management concepts till late(nuget is still in its infancy), and small to non-existent open source ecosystem. For a long time, it didn't run on anything else but Windows. Hobbyist who weren't willing to buy Windows(doesn't matter much if it comes with your system) and VS licences(express edition came late and explicitly disallows commercial use) didn't try C#.