Being productive is not a function of working 9-5 or not. In fact, some people working 9-5 are more productive than their counterparts in enterpreneurship.
The underlining thing to my opinion is having a drive. If in life one doesn't have the will or the drive, something that pushes him, he will forever slack. Be an enterpreneur if you like, if your goal is only to get enough to settle your bills, then you won't be irked to create or do something revolutionary.