I'm not really involved in professional Windows development and I generally write multi-platform code so C++ is my primary language (yeah, I know, what about Java, Mono and all that but I actually prefer programming in C++). That said, when I'm writing for Windows only, I'll often use C#.
I'm not gonna dispute your point because you clearly do need to use it but can I ask what you use it for? Presumably you're talking about bridging native code and .NET?
I could be wrong about its importance. All I can say is that I, personally, haven't ever needed it. I tried it just long enough to form an opinion not completely based on ignorance but fortunately I haven't used it again since then! Honestly, though, the fact that people are being forced to use it just makes its existence all the more annoying. It shouldn't need to exist.