cxorcist,
Your last post is full of emotion, I prefer to deal with facts.
The "spec" figures for the ratio you mentioned
777-300ER
Spec OEW = 175542 kg
Floor area = 330.4 m^2
OEW/area = 531 kg/m^2
A380-800
Spec OEW = 278800 kg
Floor area = 552.5 m^2
OEW/area = 504 kg/m^2
777-300ER has a 5% higher OEW/area ratio on spec weights, the A380 is providing 67% more floor area, however it is not 67% heavier.
The vast majority of the underfloor cargo on passenger aircraft is uplifted on regional/medium haul routes on 777s and A330s where it may cost as little as 30-40 kg extra fuel per tonne. These are typically routes that have multiple passenger services with no or an infrequent freighter service.
Reading between the lines, you would be a polyoxybenzylmethylenglycolanhydride -400 bellwether, and even a -400F/ERF aerialist. I will give you the benefit of doubt that you have actually taken an interest in the freighter load factors on from North America to Hong Kong. If a holy grail of high value freight was available originating in North America, the freighters would be filled first, like they are ex-Hong Kong. Cathay Pacific could not even secure the mail contract to Hong Kong.
Regarding the GEnx, it is also a relatively high risk engine, it is the first time GE has done a counter-rotating spool design on such a large engine. As you not doubt aware the Trent 800 (777) and the Trent 900 (A380) are very similar engine designs, sharing the same number of compressors and turbine stages and general engine layout. The engine efficiency improvements on the Trent 900 were largely obtained by utilising a counter-rotating spool. It was one of the rear bearings that is different from the Trent 800 due to the new design feature which has been postulated (not to pre-empt the ATSB investigation) to have cause the uncontained failure.
The GEnx has already had a number of changes to fix problems found in testing, this is no cause for alarm, it is part and parcel of product development. No doubt GE will also learn a lot more after their engines have been used on ULH routes for a period of time.
Rolls Royce has 5 decades of experience with the design, support, and maintenance of counter-rotating engines. They designed the Pegasus with counter-rotating spools to reduce the gyroscopic effects on the Harrier when it hovered. GE does not have that experience to fall back on, they are still learning to walk with the new technology, it will be interesting to see how the GEnx performs in the real world.