I think a lot of technology people don't understand the scope of regulatory and medical implications of working in life sciences. It's not just simple as "code it up and flip the switch!" Theranos isn't the only firm I've seen crash and bail due to that cavalier attitude.
Theranos was doing standard lab tests, like blood electrolytes. Blood electrolytes are highly regulated by the body and are only abnormal in serious medical illness. If your blood sodium level is too low (hyponatremia) that's a medical emergency and you need to be in the ER (hyponatremia can indicate end-organ failure like renal failure, heart failure; it can also indicate serious endocrine abnormalities like SIADH or too much water intake 'frat-boy' syndrome). Uncorrected hyponatremia can lead to permanent neurological disease (classically brainstem herniation).