One of the biggest issues which was mentioned in the first post, was that indies don't have massive budgets, they are trying to keep costs down and a staggered release can be the easiest method to get their game out and start getting cash in... they can get some good early PR and it helps them build momentum.
We are currently making a game, and there are so many platforms vying for attention. You have to decide which platforms you can release on from a technical point of view, such as the tools that you have available but also the staff you have to make the game and when you need to get the game out. With so many platforms, resolutions and control methods, indies don't necessarily have the time to do all this at the same time if they want to get a game out. Most indies are living with very small budgets or working full time, so it's a fine balancing act.
We want to release on VITA first (because we love the device and designed the UI initially based on it)...Once we have completed this version we would then know how to publish via Sony and we would then go straight onto a PS4 version before doing other platforms.
So because we are trying to be sensible in what we can make and in what order, the decision to release on XBO later has already been made for us by the clause, so we're not even considering it as a platform now...personally I think that is the wrong way to do things. In the end most indies are trying not champion a particular platform but just make great games on as many platforms and turn a profit so they can make bigger and better games.
Anyway it's all good fun.