LCA: Lessons from 30 years of Sendmail

Yet, despite C++ having been available for so long, there's still a distinct lack of widely-used operating systems written in it. Good system programmers are often tend to be the ones familiar with the kernel underlying their code, and that means having to have a good grasp of C regardless of what you'd prefer to code in. There's a natural selection pressure in favour of C even if there are arguably better choices.

(The first significant codebase I worked on was C++, and I've probably still written more Perl than I have C)