Actually, that is not the sorting process. Receivables and payables are first sorted by currency of the associated customers/suppliers. Within currencies, they are in subaccount balance order. I do not believe there is a third active sort criteria, leaving zero-value customers/suppliers to display in the order of either their creation or last position in the list.
Moving inactive customers/suppliers to the bottom would interfere with this scheme, which attaches priority to subaccount balance. Inactive customers/suppliers can still have receivable/payable balances.