This article in Japan Today provokes some interesting thoughts, as do some of the comments.
Certainly it's not easy to do any serious paperwork in most inn-type tatami rooms, and sleeping on the floor is an acquired taste.
Nevertheless, in comparison with the plight of some of the starving folks whose fates are supposed to be decided by the decisions and plans that come out of this conference, sleeping on tatami in an inn is luxurious.
I'm most amused by the fact that this reaction wasn't expected and planned for in advance. For such good logistics planners, the Japanese can certainly fail spectacularly in predicting human behavior...even behavior among Japanese, but especially that of foreigners.