Same logic could apply to Enron or Bernie Madoff. Fraud is fraud, even if it's perpetrated against the rich. Besides, many of the biggest investors are actually defined-benefit pension funds for teachers, firefighters, etc.
Theranos is a neat example of this; as far as anyone can see, in the early stages, its generally rather unsophisticated principals and employees geniunely seem to have thought what they were trying to build was viable. If, once this became apparent, they'd given up, then investors would have lost a lot of money but there would have been no fraud. Instead, they faked it. _That_ was fraud.
Your comments here seem to suggest that you believe it's actually okay to rob from investors. If that's what you're saying, I think you and OP are in alignment with regards to Silicon Valley ethics.
My interpretation of OP's comments was as a call to sympathy. I'm saying I have very little.