I think Musk "showed" that it's "possible" (in the short term) to just purge and get by with C or D players -- plus the occasional True Believer -- and still survive.
Let's be honest that most companies... what they're doing... is not magic. And their CEOs are likely aware that following a Google-like "hiring the smartest people" strategy along with the $$ that goes with that may not be what they need.
And during economic contractions, short-termist thinking takes often over. So here we are.
But I do think in the long run, yes, it's poisonous. But out of the ashes of that come the next A-player companies.