Whether you think it unfortunate or not (Personally I like it) FFXIV is a very story-driven game. If you went right into Stormblood without say completing the Little Ala Mhigo segment of the ARR MSQ, or the Monk Job Quests, or the lead-in quests in 3.4 and 3.5, you would have absolutely no idea what the hell was going on.

Though I do acknowledge that having to parade through the whole story might be a bit much for new players who just want to fast-track to end game. And really, Heavensward's quests, 2.4-3.3, really have nothing to do with the upcoming Stormblood.
Perhaps SE could implement specific "Story Routes"? Like rather than complete all the MSQ linearly to access the newest content, instead you'd just have to do quests A-L-Z to head straight to Stormblood?