Warmed-over "older" design that can't offer as much in the way of passenger environment improvements seen on newer designs such as the Dreamliner, A350 etc? Plus it's well known that people don't like the "flying dormitory" on here with large, unbroken cabin areas. Presumably BA can influence that with its cabin layout, although if it means sacrificing seats I wouldn't be too hopeful.
Having flown the CX A359 and A35K a couple of dozen times, the ‘club dormitory’ is still very much present.