Ever heard of Linq++ or CLinq?
Why do you feel, developers need to waste their time to learn a new language just for a single functionality?
Perhaps if people did just bite the bullet and use the better language, then Linq++ would now be even better than the Microsoft implementation and the 99% of software written in C++ (and perhaps C) could benefit rather than a select few integrators using a short sighted and gimmicky language written by a business trying to cash in on Java's success.
. Progress is not adding library xyz to programming language foo just to be able to achieve the same that another language features natively (either as part of the core language or its baseline runtime environment).
This is certainly closer to progress than "language jumping" and not actually getting anything done. I also see Microsoft's C++/CX and C++/CLI extensions much closer to progress than yet another frigging' language like C#.
C# is a waste of time and anyone who doesn't see this will inevitably be wasting other people's time.