I thought the same thing but . .. Would you want to uproot your kids from their lifelong friends and school?
Sure people do it all the time, but my guess is that is why he isn't because his kids (at least the older ones would likely protest).
I would hate that if I was a kid. My dad move around a lot as a kid and hated it so he brought us to a locale and planted us for good.
As a result, literal lifelong friends exist.
The trick is to get them in LA during the summer, let them enjoy it and make new friends and then ask them if they are ready to return to Pittsburgh ...
