Earlier quoted context omitted.
There are two things that kill my 8-hour-day productivity: 1. Meetings 2. Someone upstream not doing their job. #2 is far worse than #1 (and directly related to the parent's #1). There is truly nothing worse than a project manager who allows requirements to be delivered late, but doesn't push out the deadline for the entire project.
Lets say #2 is not a problem for the minute and you meet somebody like you. He and you do your day job in 8 hrs. But he puts in an additional 5-6 hours a day and is likely to put for the coming years. Now suddenly you will find yourself in a corner as he will grow(in comparison) inevitably. And there will be little you can do. Putting in crazy hours isn't mandatory, but neither is winning and succeeding.
Edit: If it's the money you're after I think you should try to work smarter not harder :-) i.e. if you're only way to get more money is to work more hours maybe you should find another job or change career.