Its "language-enabling" feature set sucks. Reified generics for reference types force C#'s variance model on any CLR language that wants good code and data inte

Its "language-enabling" feature set sucks. Reified generics for reference types force C#'s variance model on any CLR language that wants good code and data interop, and there is no portable good lightweight concurrency primitive. Sure Java is missing some important stuff like value types and tail call elimination (I don't think the CLR has the latter, either), both being addressed, but the CLR suffers from some early decisions that are nearly impossible to fix even if MS did show it had the inclination to fix them. Overall, Java is a more compelling compilation target than .NET, and Truffle is making it so much more so.