I find it genuinely odd that people can say this, and recognise that he's in a position that requires skill in communication, and not feel that there's a mismatch between the man and the job.

He has, for years, been poor at one of the core requirements of the position.

And then people say "but people make mistakes, he should be allowed to learn and grow" and I totally agree. But he shows no insight. He almost never accepts what he said was wrong, he almost always pushes that onto what other people understood.