Looks, good but uses TIOBE and is missing C# in second table (high-level, multi-paradigm, cross-platform, used in gamedev, webdev, enterprise, used by Stack Overflow, Stack Exchange, Unity3d, Mono etc.).
There is no IT workforce shortage in UK. Last time I checked average salaries were around 35-45 band. This is a strong indicator that demand is satisfied. At least for now.
Probably the same reason Microsoft is also promoting C++ and JavaScript (both are utterly ugly when compared to C#/F#) for Windows 8 - to expand developer base.
That's funny and sad in the same time!
If you want to try a new language for a game just do:
1) F# + NuGet + Visual Studio + ReSharper
or
2) Scala + Maven + IntelliJ IDEA
It is not about maturity - I am pretty sure first version of C# was performing better then Java back then, because C# team could learn from Java mistakes.
So can you add some dynamic code into asm.js and expect same performance? Asm.js is an assembly that looks like JavaScript for compatibility and readability.
The only amazing stuff is the distribution mechanism really. Other stuff is just plain old OpenGL but in your browser this time. It is not like it has some crazy support for raytraced voxels or something.
So it basically means that C++ got another reasonable compilation target. Not much to do with applying JavaScript to large-scale games. Also it is not HTML 5, it is HTML FF23.