The specific town came down to luck and timing, mostly. We needed a bigger house right when the market crashed, and of the places that were on our list for having decent schools/a good family-friendly vibe, this town is the one still full of big old farmhouses from the days when families were larger. So here we are, and here we'll stay at least until DD13 is off to college.
The broader region is a matter of family ties. We've talked many times about leaving but my mother needed me here, and now that she's gone, it is hard not to think about how close MIL might be to a time when she needs help as well. We may still move out of Michigan someday, especially since 2 of out 3 kids don't intend to stay in the state and DH's boss periodically brings up an out-of-state advancement opportunity, but that's a conversation for somewhere down the road.