I think the 'fiasco' surrounding the 78 was that Boeing let the marketing people set the in service date not the engineering and production people who at Boeing would have had enough experience to know that with so much new technology there was a high probability of a few serious hiccups not to shoot for an ambitions launch date.
While a very uninspiring plane to look at -graceful wing plan form aside it seems to be popular with the airlines who are using it and who themselves do not seem to be having serious entry into service problems with the aircraft.
Building airliners is always about the art of the possible and so there is little justification for betting the marketing people do more than come up with a silly name and make there there area few 8s in the model number as they somehow think Asian airline VPs would be influenced by stuff like lucky numbers.
Both A and B and the engine companies build amazing creations utilising an incredible range of technologies for an often un-appreciative audience /end user base
PB