How often do people that need to write device drivers need to use a high level language? Is there really a lot of demand for this sort of thing?
In real life, you're right. It doesn't make sense to try and mash every language together just because. Its also potentially not possible anyway, since theres too many conflicting design decisions - though the ability to mold a language, through powerful abstractions and macros, like Lisp does, does indeed solve a lot of this.