I've known people who were hard workers, but not terribly ambitious. They were great at what they did, and always made sure their output was the best quality possible along with seeking out ways to be better at their jobs and make themselves more effective. However, they didn't necessarily want a position with more responsibility or to advance in their company. They were happy where they were and were content to be allowed to stay in their position indefinitely rather than being promoted or making a lateral move to a different team or part of the company.
On the same note, I've known people with plenty of ambition, but who weren't willing to do the grunt work and the primary job functions they were hired to do. Instead, they focused on doing projects and work that would get them noticed and would look good on a review, rather than the mundane tasks that won't make a person stand out (even though someone has to do them in order for the team or company to fulfill its mission).
I don't blame anyone for wanting to be promoted -- I want it as much as anyone else. And I know that a lot of people with ambition realize that hard work is essential to getting where they want to go. But it's important to recognize the difference between wanting to have accomplishments and recognition, and wanting to be good at what one does.