I think it’s important to understand the difference between product/engineering skepticism (eg, it will be hard for a new entrant to build a great smartphone; it will be hard to break into the taxi industry with an app) and fundamental scientific skepticism based on a claim of some major scientific breakthrough. These are vastly different things, and (in my understanding) experts correctly realized that Theranos would have needed the latter for their product claims to be true. This is what the investors failed to internalize.

I know it’s popular (and sometimes true) to blame scientists for failing to adopt new ideas, but I don’t think you get to play that card in a situation where the alleged ideas are being kept secret. And yet many do play that card. As a scientist if someone arrives with a product that implies a massive (but unpublished) scientific breakthrough, then I’m going to express polite skepticism until they publish their results. If for whatever business reason, the startup wants to keep their breakthrough secret (rather than publishing and patenting it), well that rings alarm bells — but even then surely the investors can hire outside experts to review the science under NDA. If the startup refuses even that, then I think you need to accept that the most likely possibility is fraud rather than someone figuring out how to bypass the laws of thermodynamics or whatever.

Are you suggesting the scientists in this case didn't give good reasons?