Consider for a moment that locking new areas and jobs behind MSQ also means that there will naturally be fewer people crowding up the new areas at launch. There will already be a ton of us there, do you really want hundreds of Lannisters and Targaryens, who fate grinded to 50 without a single dungeon or job quest, crowding up the place trying to unlock their dragon mounts?
I'm sure at some point they will remove the MSQ requirement from the 3.0 zones to aid new players in accessing relevant content. But that's the kind of change that will occur around 4.0 or 5.0. For now the MSQ is in place to benefit US... the players sitting at level 50 who are hungry for more content.
