Stability. Once you start to build a family and lay down roots the harder it gets to be able to move because you have to put family first. What may be 'better' for you might now always be better for the family.
There aren't a lot of jobs in the area either. My wife and I have discussed moving down the coast to Raleigh/Durham area since there are a lot more jobs around there and we have some family near there. But I imagine it would be hard to apply and get interviews for jobs when you're not in the area.
My wife says if we are to move it has to be in the next 2 years - before the kids are in middle school. The thought process there being that they will solidify friendships, clubs, sports, etc. before high school.
Since I've moved into management it is hard to apply for remote jobs that look very appealing career-wise. I fear employers see the management history and think "this guy hasn't coded in years".
So many factors to take into consideration that it numbs you into staying.
And it's not like the jobs we're talking about here are completely "dead-end" (I wouldn't call a well-paying job a dead end and I definitely have one of those).
As an example, I got an email this morning from Whitetruffle mentioning a company was interested in me (which is always a nice boost to hear) for a position. However, the position was in New York City, and I live in Southern California. Researching the company, I find the salaries offered are probably so-so. Work-wise, I have no idea how it might be (it could be great, it could be similar to my current place, it's hard to tell because of that "grass is greener on the other side" one starts to get after being in one position for a while and seeing all of the neat new companies that come up), but in general I tend to look at the big picture of how such a job would affect me and my family.
In my case, the reasons for staying in my current position are definitely a combination of stability (working for a public college provides certain benefits in that regard for pension/job security), my current pay (at this point I can't really move to any other local organization because none of them would pay similar to what I'm paying now...I would be forced to somewhere else), liking my small town commmunity, being able to be close to my parents, and having a small family (one 6-year old daughter with another on the way).
A few years back I took an opportunity to go up to the Bay Area and work for eBay, but I was uncertain about job security (combine the Glassdoor reviews mentioning mid-year staff cuts and my own impostor syndrome feelings made me feel like I could be one of those people), work-wise it actually wasn't more fulfilling than my current position (I had a lot more freedom to define my own projects and work at the college)...plus the salary wasn't really much more than I had already been making when I factored in cost of living changes...then to top it off my family was much further, and my wife (fiance at the time) and I weren't living together so that added additional stress.
So in the end, I ended up making the decision to come back to the college (and luckily it was to a slightly upgraded position).
It's not perfect, but overall, I definitely feel like I made the right choice.
Would I love to work for a startup? Definitely! I think there's a ton I still want to learn and can learn, but at the same time I don't want to place myself or my family in any sort of bad financial position because I don't know the future and which company out there would be even more perfect than my current job.