^ The same picture, minus games releasing after May. Two of them are different versions of the same game. And then there were 7.
So, here is your answer:
1, COMG favors Sony. It's not a matter of bias, but demographics. COMG just gets more Sony customers.
2, Nintendo doesn't put their games up for pre-order until just a few weeks before release. If they were as frivolous as Square-Enix, you'd probably see Pokémon X & Y up there already, among other games.
3, 3DS and Wii U are still the new kids on the block. Development hasn't entirely shifted to next gen yet; right now, as you can see, PS3 is still where it's at, because it's still going strong and it has a 9 million install base in Japan (which 3DS has only recently passed).
Maybe towards the end of this year going into next year, we'll see more 3DS/Wii U games, or maybe not.
