And it's not from lack of trying on Boeing's part either. They would want nothing more than to sell the replacement. One day while sitting at my desk in the Airport Compatibility group I get asked to make a drawing of the ramps at MEM and SDF, re-pitching every Group IV wingspan parking spot for Group V, then stick a 777F there and see how many spots they would lose. If I had time they also wanted the smaller hubs like IND and ONT. Apparently it was in support of a sales campaign to replace the MD-11. Then they asked me to lay out the regular ramps but everywhere an MD-11 could park, put a 767-400. I did a double take. A 767-400, that hasn't been in production since 2005, not -300F? My lead engineer confirmed that he did not stutter. Some crazies much higher up were willing to offer a 767-400F, re-engined with GEnX engines, if they could get FDX and UPS to commit to get rid of the MD-11s. Something about having a closer cargo capacity and the -300F being too small. I did the study but it ultimately went nowhere. Either they didn't get interest or figured spending all that design capital for such a niche product wasn't worth it even if they could sell it 1:1. Although I'm sure Southernjets would have ordered 100 if they offered a passenger version, they love a niche, orphaned aircraft that nobody else wants.
Sorry to derail the discussion on this tragic incident. It hit me hard too, and today was my first day back on a trip after it happened, but this anecdote suddenly popped into my mind seeing all the MD-11 replacement talk.