The Problem with ARR Progression

[Iscah]

SE decided to include a wall only because Titan(Hard Mode) was required in the MSQ. However, this also forces you to unlock Ifrit and Garuda Hard Mode for absolutely no reason.

I think you're looking at the requirements back to front. It's not that they wanted to make Titan a requirement and the others are "just in the way", it's that all three are required and that clearing Titan means you've definitely cleared the others as well.

As others have already said, the requirement is there because otherwise the Scion NPCs have to remain at the Waking Sands until you've completed their quests.

The forced completion point is also not the ideal time to do the quests - just the last chance to do so for continuity's sake. They're really intended to be done as soon as you complete ARR and Minfilia has both the unlock quest and the first 2.1 MSQ quest to give you. Consider it "2.0 post-credits content" before the patch storyline begins.

Ideally when they tweak the ARR script, they'll just make it part of the MSQ sequence so people do it at a fixed point instead of being forced to backtrack to it later.