It's a wider take on [Goodhart's Law](
https://en.wikipedia.org/wiki/Goodhart%27s_law):
- young female founders running successful businesses appear to be exceptionally skilled because they have been fighting against the current for their entire life. And the future of that company is double-boosted: They have an exceptionally good founder at the helm, and that founder is going to get even more free media coverage than they normally would.
- ... therefore if I see a young female founder, say no more, I will extrapolate from historic facts and conclude that the company is highly likely to be successful.
- ... and Goodhart's Law kicks in. Whether it is because those with intent to defraud realize what they need to do / they were always around but are now no longer filtered out, or it's simply because the Constanza-liars (they believe their own lies) are not being reality checked anymore doesn't matter: The measurement tool 'is a young female founder' has lost all its predictive power.
- even worse, if the relevant parts of society (the editors of financial newspapers, the bigwigs at investment corps) don't sniff the change in the wind fast enough, we get a new oversimplified yardstick: Someone is going to conclude 'might as well treat every young female founder as a fraud, because statistically they probably are!'
I think your innate sense here is the right answer: The original sin here is treating the identity of the founder as the only significant aspect. Not a heck of a lot of inquiry and skepticism about the promise of Theranos was required to start unravelling that whole mess.