I didn't think it was all that ugly, certainly not as ugly as the A380, but here's the part pilots didn't like:

Pilots loved the roomy cockpit with large digital displays, but were less enamored of the plane's nervous temperament. The MD-11 was famously hard to land, and especially balky when the wind came from its side. Landing crashes accounted for five of the nine MD-11 accidents. According to data published by Boeing and updated through 2013, it had had 3.62 accidents with hull losses per million departures, far more than contemporary large jets. The MD-11 was almost four times more likely to crash, statistically, than the Boeing 747 series 400. "The flight deck was the best I've worked in, but as far as aerodynamics, the plane didn't fly well," a captain for Italian airline Alitalia, who asked to remain anonymous, told International Business Times during a flight in 2007 aboard a Boeing 777, the airplane that largely killed off the MD-11. Able to fly farther and with more passengers, but using just two engines, the 777 was much more fuel efficient, and swept up the market for medium-to-large size long-range widebodies. The trijet's sales disaster was a prime cause in the demise of McDonnell Douglas, which was bought by Boeing in 1997.

Delta had 5 'hard landing' incidents, each with major damage to the tail. All 5 were done by Instructors or Line Check Airmen. I treated it with great respect and never had a bad landing, but I kept one eye on the CG, as if it was aft of about 28%, it would swap ends on you in the flare, you had to be ready for that and not pull back too much in the flare.