C/C++ is a language with limited facilities to ensure correctness at compile time. The languages are riddled with undefined behavior in common features that programmers with multiple decades of experience still get tripped up by. NULL access - the so called "billion dollar mistake" - out of bounds reads and writes, and use after free create a litany of security issues and create massive liability for companies who choose to author software in these languages.

Not what you want to hear about an operating system :p