Never thought of it that way. Of course, I wouldn't call it a language smell, rather a framework or library smell. C# isn't complicated. The frameworks and libraries on top of it are a bit much, and that's where the IDE really helps. C is a small language, but tack on a framework and you aren't learning C as much as you are learning the framework. Same things for Rails.

Of course, no one is going to use C# without the frameworks and libraries added in, so I guess you almost have to include the IDE support. But then, seeing what VS 2010 can do makes me wish Eclipse or Netbeans could do it as well. Couple that with the fact that Eclipse and Netbeans feel so heavy and clumsy compared to 2010 despite 2010's size and beta status.