The problem with Juciero and Theranos isn't that they failed. The problem with them is that Juciero was an immensely dumb idea that was never checked or questioned and thereby wasted tons of money, and Theranos was so unabashedly, obviously mustache-twirlingly evil that if it were used to script an evil corporation for TV, I'd have called it unrealistic (and thereby, it wasted tons of money). They're the worst parts of SV (dumb companies offering things nobody wants at outrageous prices, and obvious evil pretending things are OK because they're 'changing the world' or some other nonsense) exaggerated to near-comical extremes.
Silicon Valley's problem is deeper than failing businesses or not enough diversity. It's that the entire enterprise is a bold-faced moneygrab for VCs; ethics, diversity, etc. were never really part of the point, and it's only now that the rest of the world is starting to figure that out. SV's problems are at the core of the reasons for its current existence.