You see code size and linearity is very important for anything non-trivial and hot. New languages tend to have abstractions built upon themselves making understanding and optimizing a pain.
Well, I have plenty experience of working with SBCL which directly gives you access to the assembly produced, allowing extremely good control of the code quality in hot spots. Just
(disassemble 'my-function)
would give a nice printout. There are also lots of other languages, which might be high-level, but still give you excellent code quality - I used Modula-2 a long time ago which did back then beat the resident C-compiler in generated code quality. Yes, many C compilers are very good and some new stuff not much so, but claiming in general that "C" is fast is an oversimplification.
