Perhaps not the general public, but everyone in the clinical lab industry knew that there was no way that Theranos could achieve accurate results with a tiny blood sample. A single drop of blood extracted from just under the skin is not representative of the blood in the patient's circulatory system and contains too many contaminants. This is fairly straightforward biology and has been know for many years.
True. Still, Theranos happened and flew fir quite a while. The problem here is the smaller the population of people able to judge new tech (which is generally speaking getting smaller everyday tech becomes more specialized and advanced) the longer it takes for reality to catch up with the money.
Which also means that it is ny impossible to distinguish between a growth company with a solid product and one that is just trying to out run reality.
But I read on these very forums, by prominent posters, that the only reason we were skeptical of Theranos was that we didn't want to see a young woman succeed! What happened?