That's fair. That said, the fact that writing a BLAS implementation in a high level language seems like a favorable benchmark does kind of show my point that for numerical computing, Julia is really fast (especially for a high level language).

As a general purpose language, I'd probably categorize Julia as fast, but not crazy fast. Numerical computing is definitely where most of the man hours have gone into development. As a general purpose language, Julia probably ends up at around the same place as C# (not as fast as C++, but still pretty respectable). That said, this is an area where the main thing Julia needs here is more optimization on some of the libraries that already exist, and some new libraries to extend the language's reach further. I don't think there's anything fundamental holding it back from getting closer to C++ performance in general computing. It uses the same compiler (LLVM), and it's pretty clear that you can get Julia to output the same assembly code. It's just a matter of having enough devs pushing ecosystem forward.