All those Glassdoors reviews talking about long hours of work, working late, and for what? What did all those people work those long hours for? For complete failure. Theranos is in shambles, and these people signed up to work and work late at a company that was a fraud. Requiring employees to work late, or to strongly encourage that kind of behavior is a huge red flag for me when looking for work. People wasted hours of their life at this place, away from family and friends and personal time, all for Theranos, a name that's a joke now.
Easy to say with hindsight. What if it would have worked out and their tech had revolutionised medical testing?
Failures are as important as successes, and nothing to be ashamed about from the employee perspective, just the covering up by management that's the problem.
This is anecdotal, but in my experience, the complaints about "everyone working long hours" is usually a sign of either:
a) Poor planning on the part of management, resulting from not enough resources or hires
b) Poor market performance, leading to having to squeeze more out of the existing resources to get the results originally projected to the investors
Certainly there are people who like to work long hours and there are jobs that will give them all the work they can want, but those typically aren't the people complaining about it.
When I've seen things like this on Glassdoor, it's almost always a company that's closing in on a spectacular failure. It's like almost some kind of evidence of a specific kind of leadership driven failure mode. Theranos didn't fail because of lack of market demand, or even the failure of their tech, they failed because of how they were run and these kinds of reviews seem to be specific pointers to this kind of management style.
Anecdotally, I once worked for a company that did this same thing and the feeling in the company much more closely matched the longer-form negative reviews than did the astroturfed reviews...all of which were written by one H.R. exec shortly before they were let go from the company.