I will answer this from the perspective of personal experience.
I've been in the same position for 12 years now. Here's why:
When I started, my wife gave birth to twin boys. The economics of childcare dictated that she stay at home with them for several years. When she went back to work, I needed to remain in a stable as secure position for a couple of years until her career path stabilized.
Guess what. She hated that job, and started searching for another. This set back my timeline another couple of years. Then the world discovered something that I already knew. My wife is awesome. She was poached, and given a much better job with another company. Again, we decided that I should wait a bit before looking for new prospects.
Why am I so complacent in my current position?
I work for a small company with great people. There is no other position here for me. There's no one else to manage. I work 9 to 5, and maybe a weekend a year. They accommodate my involvement in Boy Scouts, giving me time off for camps.
My career has progressed. I'm now advising the company what we should do, rather than being told what to do. My salary has more than doubled over the time, and I'm receiving regular bonuses and dividends on top of that.
What has not changed is my title. And for the most part, that doesn't matter.
Am I not ambitious enough? It depends on how you define ambition. My family is certainly better off having me home evenings and weekends. My wife's career has taken off, partially due to my support. Our family has thrived because of the stability and security this company provides.
At this stage, I'm scanning what's available. And if the choices I've made raise a red flag during an interview, then so be it. Their loss.