My educated guess is that the NC return used to pick up the Federal account information, and then the state of NC said "No, make them put in the NC account separately and twice, because no one ever uses copy-paste, and rekeying by hand means fewer errors!"

See also, stuff that various states have requested not proforma, because "some poor clerical person at the tax preparer's office will pull up last year and this year and copy-paste - hopefully accurately!" is not the workflow that the state assumed would happen.