The Airbus fiasco has little to do with the size of the aircraft, and absolutely everything to do with excessive schedule delays. That same problem will probably kill the 747-8 passenger edition ("intercontinental") as well. Airbus bit off a bigger technical challenge than they realized, and had multiple lengthy schedule slips. Airlines don't like it when their equipment is years late. This says nothing about the quality of the aircraft.
Boeing had a big schedule problem as well, related to their supply chain. Again, if you were an airliner needing a big intercontinental aircraft in 2007, and 2010 rolls along and your order hasn't been filled, wouldn't you go for a 747-400 or A350 as well?