I read stuff like this all the time, but this take is actually extremely reductive. (Otherwise, every moron out there would be making 7 figures, but they don't.) It's not as if these folks are utterly incompetent in their roles, but in fact they optimize for things you think don't matter (but actually do.) For example, if you can get a promotion just by knowing people, why would you optimize for building a better product, when you could optimize for getting a box and inviting C-execs at a football game?
To wit, sitting on a board is often "free money" and those positions are purely obtained by networking. Life is much more of a popularity contest than people (especially engineers) want to believe and EQ pays off much more than IQ does. We are, at the end of the day, social creatures.