Assuming F# is included I actually agree with that to a large degree except for the fact that the division between C# vs. OSS languages is more ideological than anything else.
Sadly F# is taking C++'s place on Visual Studio's list of not so loved languages.
Although many financial systems are picking it up, and a wealthy community is building around it in the .NET world, Microsoft development tools team still seems not sure how to steer it.
MS painted themselves into a corner with their marketing message. They can't really come out and admit F# is superior to C# in practically every sense. Apparently now, the C# lead designer seems more interested in patching up JavaScript than actually catching C# up to the state-of-the-art.
Meanwhile, MS has marketed F# as "financial and scientific". Remember the F# team lead is also the main force behind getting decent generics into the CLR, a concept MS corp had dismissed as "academic". So it's no surprise they aren't continuing that line of thinking.
