Just compiling a dynamic language doesn't magically give it the same performance benefits as a static language. The real problem is the semantics of the language, not the process used to run it (although obviously that does have an effect).
I couldn't agree more with both aspects of what you just said.
Wouldn't it be possible to do it also with Swing ?
Swing can interface with JOGL for 3D, yeah, but that adds external dependencies, same with C#, at least with Java it's a part of the core API from Java 7 and up.
Windows forms is outdated, it has been replaced by WPF (c.f http://en.wikipedia.org/wiki/Windows_Presentation_Foundation)
Silverlight is dead, it's called HTML5.
Microsoft Silverlight provides functionality that is mostly a subset of WPF to provide embedded web controls comparable to Adobe Flash. 3D runtime rendering has been supported in Silverlight since Silverlight 5.