An example of why I feel this is sometimes necessary, picture a millionaire with an ex-spouse only capable of earning minimum wage. Do you think they could afford to live in the same school districts, allowing for a viable joint placement? Probably not AND we'd have the kiddso living in one parent's mansion half of the time & living in the getto the other. You'd have them wearing used hand me downs to school on the days they were with their poorer parent & designer clothes on the days they were with their richer parent.