Too expensive to operate / purchase when compared to the twin jet 767, A330 and larger 777. And smaller than the four engined 747 which has a larger passenger capacity. Basically it has been squeezed out by these types and as values have dropped it now becomes an economic proposition to convert to cargo config. Lease rates for passenger aircraft however still higher than the DC-10 so Scandic unlikely to go for them. Plus difficulty getting them onto UK Register (if required).