Healthcare is one area where many people (particularly Americans) have the absurd idea that everything has to work perfectly.
Think of the level of indignation people feel when a surgeon who spent 15 years beyond college doing advanced training (for little pay) makes a small mistake that costs someone's life. Or an OB misjudges something and ends up in a major lawsuit.
But for other jobs, mistakes are a part of life. In software we are proud to decrease our bugs through testing and improved techniques and processes, but nobody expects perfection. Even mass market products like TurboTax ship with tons of bugs. Lawyers routinely let innocent people wind up in jail out of pure incompetence.
We need to get over it. Theranos is doing something very smart and while it needs some additional refinement, it is pretty clear that doing large scale blood testing/monitoring is the future of diagnostic medicine.
The irrationality we have about healthcare being perfect is a) false (mistakes get swept under the rug all the time) and b) counterproductive because it gives us a sense of mastery over our destiny that we simply do not (yet) have.
Let's also not forget that medicine is plagued by a very irrational risk aversion, which is why many useful treatments are available around the world but not in the US.