Maybe you should trust the judgement of the highly-qualified engineers then when they decided to go with their own toolchain, and not just assume that they’re doing it because plan 9 or some other vacuous reason.
He falls under the "and/or did not research established options in other language as per their admittance" part of my previous statement. Not to mention that B nor C encompass lessons learned since their design.
Imagine what Ken Thompson could have accomplished if he hadn't made all those poor design decisions!
And yet hundreds of thousands of working programmers around the world are productively using Go while still continuing to ignore the supposedly superior solutions.
Appeal to authority fallacy. People still use C, what's your point? There are superior options, but people are either (1) forced to use something inferior, or (2) don't know any better (especially if they drank the kool aid).