(Sorry should have said 9 abreast above rather than 10!)
Boeing designed the plane expecting a 2-4-2 configuration to be used in economy. I realise its the airlines choice but Boeing shouldn't have agreed to squeeze that many in. It reflects badly on the Boeing and the aircraft and it was amazing just how unhappy the entire cabin was.
BA have to their credit acknowledged they have a problem with 787 seating following terrible customer review scores from their 787 flights. Its time other airlines did the same.