Nation owned is still publicly owned, not ran by workers.
This is exactly the same thing that happened to originally collectivist farming in Soviet Russia - it quickly got nationalized or virtually nationalized by centrally mandated quotas.
This is why I wouldn't blame it on socialism per se.
It was the stated goal of the socialist government however to get there. And I'd rather argue that this aim partly caused the outcome.
In fact I feel this is the main miscommunication that causes the "it wasn't real X" debate. People use the term X to refer both to the goal and the method of implementation.