I feel the cross gen thing is much less of an impact on the basis that every owner of a 360/PS3 knows that they will eventually need a PS4/XB1 to keep playing new games and that they would be getting a large scale experience upgrade by buying the new boxes, even if the games were the same.True- I thought those titles also being available on PS360 as well as XB1 would lessen that impact. I think what happened is there was a definite market for a new system, and Sony has taken most of that market.
With the Wii U by comparison there was almost no upgrade and people knew it wouldn't run nextgen only games so having no core third party game exclusives was much more painful.
With the PS4 in Japan there is almost nothing to buy even if you wanted one, and the mid term outlook is super grim.