I would think they aren't all that correlated. Look at apple, Steve job treated some of his engineers like crap and they were successful. Its nice to have a good place to work, but I don't think it ensures success.
a) the concept of 'tough love' is applicable
b) were engineers allowed and challenged to innovate? or did their work effort primarily consist of navigating red tape and beurocracy to the point that all creativity was crushed?
etc.
see also: dilbert.