Oh dear... Some casual observation of the Japanese aviation market demonstrates quite clearly why larger planes are not necessary.

1. Airport capacity in Japan is going up, up, up. In the last 12 years we have seen new airports at KIX, Chubu, and Kobe. Plus new runways at Haneda and a second runway at NRT, leading to more slots at both airports. And isn't Kitakyushu coming on line soon?

2. There has been a huge shift away from 747s to 777s domestically. Itami-Haneda used to be almost exclusively 747. Now it's almost all 777s. Haneda-Sapporo (which I believe is the busiest route in the world by passenger count) used to be almost all 747, now it is majority 777. Same with Haneda-Fukuoka, plus many other markets.

3. Even at NRT, many routes have been (and continue to be) downgauged from 747s to smaller widebodies. UA used to be 90% 747s. Now look at all their 777s. NW has switched many 747 flights to A330s. AA and CO are all 777. Even JAL and ANA are dumping 747s from some of their flagship routes, i.e. LHR (now only 777s on JAL), FRA (777 on JAL), JFK (777 on ANA), LAX (777 on ANA), SFO (777 on ANA), etc. etc.

4. The Japanese population is declining. It is no longer a growth market.

That fragmentation is happening is clear to anyone paying attention. It's right here in front of us.

Yes, there is a market for the A380. But that market is a lot smaller than the A380-boosters claim. And I really, really doubt the Japanese airlines will order any.