I think ending MD-11 production was a great strategic move for Boeing. My hypothesis is the following:
Now the MD-11 is becoming very popular as a freighter, its second hand price will be high. So it will make sense for many airliners to sell them off. And since McDonnell-Douglas became Boeing, they will be doing business with Boeing. Boeing can make a great package deal with airliners buying the B777 as it trades and modifies MD-11 aircraft. This makes Boeing very powerful, as competition with the A330/340 is very fierce. In terms of performance between Airbus products and Boeing products there are almost no differences. So winning an order will be all about making the best deal. Airbus will not be interested in MD-11, so with most deals replacing MD-11’s Boeing will be making the best deal, consequently replacing the MD-11 with B777’s. That means big money for Boeing and that is what it is al about!!!!
Smart thinking of the Boeing people when they decided to end the MD-11 production.