You can't know if you are going to succeed when you try to achieve a revolutionary feat. But you have to act like you are sure you will.
Imagine Jobs in an alternate universe, trying to get out the iPhone, but after years of failures and billions wasted, the world realize the product vision was unrealistic.
Basically him being the same asshole, but hitting a wall many predicted.
That would look the same as Theranos.
The difference is that Job didn't fail. But he couldn't know that before trying and commit many people and resource to it.
Imagine Elon failing as the Falcon X. Or worst, failing over and over until his company died because they lost control of one that went crashing into a school.
Imagine Zuckerberg called out about all the privacy issues on FB before it actually made benefit. I would have died.
When you try to achieve radical vision, you often either succeed as a hero or you fail as a vilain.