it should be painfully obvious.
you bring in a new staff to atlanta.
at least some, if not all, the staff members have a wife and kid(s).
as soon as petrino leaves, you think the entire staff is going to be kept on by whoever replaces petrino?
hell no. so pretty much everybody who relocated their whole family to atlanta was going to be stuck with no job... and then if/when they did find a job, it would mean having to uproot the family (AND KIDS) again.
not a really cool thing for kids to go through.