Is it legal for a creditor not to accept the full payoff of a judgment choosing to keep it on your credit report with no intentions on executing it?

It's not illegal for a creditor to refuse payment in full, but it would be a very unusual for them to do so. A possible problem might be that the debtor is attempting to make an agreement to pay the account or judgment if it is removed from the person's CR, however, that is not possible. An account that is paid in full that contains adverse information will remain on the credit report for the required seven years and be noted as "paid as agreed" or "paid in full". A creditor or collection agency cannot have the account removed from the report once the entry has been made. A paid judgment will also remain on the CR for the required seven years even though it has been paid.