Family ties are indeed extremely strong. However, here in Idaho we have lots of former Californians and it seems that it only takes one family member to make the "leap" to move up here, and before long (usually within 5 years) the other members start to see the benefit and move themselves.
My grandmother just moved here after living 80 years in CA. The family next door is 4 generations, each gradually moving up from CA.
The reason is the same: Family. But once someone made the leap, the others followed.