#1 cause: lack of a mature organization. No clarity, no process, no structure, constant uncertainty and bosses that clearly have no idea what the fuck they are doing.
Collective ownership, treating employees like entrepreneurs even though they are very different people with a different mindset and different coping mechanisms is not just misguided, it's downright destructive.
Employees are not entrepreneurs, they have a different mindset and different coping mechanisms. They can handle the uncertainty of a starting company that may very well fail, they can handle long hours, but they need certainty about the nature of their job, what is expected of them and their coworkers. Not having that structure makes them extremely vulnerable to any kind of stress, stress that a startup job is guaranteed to have.
It frankly pisses me off how badly employees at startups are treated by not recognizing their needs as employees. No amount of toys, free snacks and other gimmicks will compensate for that.