Historically, the "turtles all the way down" approach has not been very successful outside of niches. Lisp, Forth, Java have all been used for OS's that never seemed to go anywhere.
I'd much rather see three distinct languages, with a shared base syntax and style (ie, common formatting of comments, common scope delimiters, common operand behavior - something like C / Java / Javascript).
That way, you could have your low level language use pointers, nullables, inline assembly, goto and other "dangerous" things that are the most efficient ways to do stuff. You wouldn't want to have that language crippled like modern C++ though, you would still want modules, a well planned object oriented syntax, a better solution to name mangling, and better readability.
You could have an interpreted Java/C# esque applications language that would mostly be similar to modern Java/C#, maybe with auto, a better namespaces implementation (in C#, a class defined in two places with the same namespace and signature have situational behavior that gets really messy, for example). You would use this language for the application layer.
Scripting could just be an autoboxed dynamic language like Python. Maybe have a whitespace significant and insignificant dialect. I'd like to see dialects of such a language, where the context it runs from dictates available modules. Since it would be permissions based, it could function as a shell, web, and glue language depending on where you use it.
I do agree on this sentiment though. The wide base of languages in modern computing makes the whole thing a lot messier than it needs to be, and the lack of any full stack that really ties together nicely and is well thought out without the smudges would be really nice.
