I think I see a opportunity for something new here.

Why isn't there a uber secure OS written in a high level language that would prevent easy privilege escalations, vulnerabilities caused by buffer overruns etc?

It would be nice to have a standard security approving body (like FCC) that gives out graded standards.

It is like every generation forgets the mistakes of the past and repeats them. When $5 Raspberry Pi is powerful enough to run desktop OS, I see no reason to not adopt a high-level language that prevents basic security violations at the roots.