The question is why? what conditions need to occur where a man who most likely can get another job easily enough and who has switched jobs before decides that ending his life his a better course of action then switching jobs.
They wrote that he eventually saw a psychiatrist, was he prescribed SSRI medication (I.E. Prozac)? If so, the other articles on HN suggest that that may be the cause, and not Uber's work environment.
All of that isn't to say to Uber's work environment is ok, but unless there was some form of coercion to keep the job (debt, noncompetitive wages, medical insurance issues), I don't think it's fare to blame Uber for the suicide. Mass worker exodus or a union is the way to change a company's work environment.