So why did Peace Walker have to be made again when most of these questions can be answered by other entries in the franchise?
That sounds like you think a game needs a reason to be made in order for you to accept its existence. But again, like I said at the end of my response to Shattered Dreamer, I don't think it's an issue of hanging plot threads. After all, questions might be better left unanswered, as that was how a lot was supposed to be left in MGS2. But Kojima's proved through SE and PW that there's a lot of awesome things you can do with that back story. Do I want there to be 5,000 games about Big Boss? No. I agree that David should get some rest, but I would absolutely love to see another BB title. I mean the last game can be played in its entirety co-operatively, that's a pretty huge deviation for the franchise. And I'm craving a new Metal Gear Online outing because of just how good it was in MGS4, especially with their post-launch content.