There's a few options. The easiest to understand and the least likely is that they like being the big fish in the small pond. They enjoy being in demand from ev

There's a few options. The easiest to understand and the least likely is that they like being the big fish in the small pond. They enjoy being in demand from everyone around them. More commonly it's a lack of ambition and a comfort with where they are. They're happy with their environment, they don't want to to risk the change and they don't see why they would. They may have only worked in that sort of place (or only in that one place), and haven't seen how much greener the grass might be elsewhere.