Not sure where you have worked, but that's not most people's experience. You can have all the ambition in the world and with the wrong environment or culture you will slam into a brick wall very quickly. And sure, you can change jobs if your skillset is in demand, but guess what-- most other orgs function exactly the same. In fact, the people who are willing to compromise themselves most are often the ones who get ahead. That might be what some consider "ambition."