Cough, without too much thread drift, on previous aircraft programs the Product Development people would come in with a wish list based on things they've been working on. Then those of us with real world experience evaluate their wish list to determine what's reasonable and practical, then throw out the rest. On the 787, the PD people and bean-counters were given free-reign and the rest were told to make it work - basically throwing out 50 years of lessons learned in the process.
I've been in a few 787
post-EIS design reviews (
), and a common theme was "What the
were you thinking? We had a beautiful system on the 777 and you totally F-ed it up for no benefit!"
IMHO, the N2 gearbox falls into that category, although it could have been worse - at PDR they had a clutched drive between the N2 and N3 shafts for starting that would disengage after the engine was running. As I suspect you can imagine, the failure modes were horrid - fortunately it turned out to not be needed and deleted...