I think the big problem is that as one of the comments pointed out, that Nvidia is the sort of company that is only as good as the talents of it's people. What it makes comes out of the heads of it's staff, and if you can't attract or keep good people because you treat them so badly, then Nvidia has a long term problem.
A lot of those comments do explain the base reasons why Nvidia has been failing to execute. This kind of overwork, ass-covering, people leaving, management problems will cause these kinds of issues when things don't go perfectly. I'm sure any of us that have been in IT or engineering projects have experienced some of these failures in our own working life.
Having said that, a lot of those comments are the sort of things you hear from people in a lot of other companies. That doesn't mean that Nvidia doesn't have problems, just that they have the same issues as a lot of of other companies. However, these other companies are not world-leading companies who should really do better by their staff.