What I see here from some people, is attempts that seem thinly disguised as "support for small developers" basically saying don't force them to support more then one platform ( within a release window?). When in reality, it's totally up to the developer if they want to release on more then one platform. Only developers serious about platforms will approach with that idea.
This seems misguided to me. You could even view some of the arguments here as people arguing for games to "not be multi-platform". Which totally goes against supporting small developers. I think there' a mixture of:
a) What benefits the consumer
b) What benefits the developer
c) What benefits the platform holder
There's no solution that benefits all three items above.
I buy games, for me the consumer it would benefit me to have games released on multiple platforms at the same time. Its gives me choice of which platform I want to play the game on.
As a developer it would be best to launch on multiple platforms at once, if I can't do that, then I make staggered release dates fully knowing that sales may be diminished ( due to reviews, problems with the game, or simply the game hitting the right subsidence) on the second platform (due to launching first elsewhere). I have to weigh cost versus benefit of supporting the second platform. If I can't reach that point of supporting two or more platforms, or if I don't want to strive for that point, then I become platform exclusive.
As a platform holder, I wouldn't want a game released on the competitors platform before my platform. It gives them an advantage, gives my consumers a disadvantage. I would prefer exclusivity for my consumers, and if i can't get that, then I ask for multi-platform release.
People saying this hurts indies, doesn't have the full picture. Indie doesn't only mean 2 guys coding a game in a basement anymore, Indie means independent developer ( take HB studios for instance), there's lots of studios out there that are fully capable of multi-platform release. Studios too small to tackle two platforms, simply won't. They won't risk closure to support a second platform if the title hasn't done well enough. If it has done well enough ( and I mean really well ), they would have the money to support more then one platform at a time, grow and expand to accommodate the ability.