If they were to restart the DC-10 line, they'd have to do some major re-engineering because the systems and such are 30+ years old as designed. They'd probably start with the engines, and since they are much more efficient today than the original GE
CF-6 they started with, they could hang two larger engines on it and do away with the third engine, saving a lot of fuel and maintenance cost. Then the wing would have to be redesigned because it just wasn't as efficient as the wings used today. Finally add new electronics for the cockpit, do away with the Flight Engineer's station, add new IFE, more efficient air conditioning units and.....
wait a minute...
we just designed a 767/777/A330 clone!
, sorry for pulling your leg just a little. The truth is, just as some of the previous posters said, the DC-10 was great for its time, but now there are simply newer and better airplanes for the offering. Airlines are businesses and don't get very sentimental about old aluminum (OK, maybe the Concorde, but that's it). They want what will cost them the least for getting the most people where they want to go.
One smooth landing is skill. Two in a row is luck. Three in a row and someone is lying.