Level 50 quest from AAR to Heavensward is just too much.

[MistakeNot]

A friend of mine started playing a few months back, was enjoying the game and was hoping to be a Dark Knight...but it was such a long, slow process that he lost motivation. He hit level 50, finished ARR 2.0 and was super excited to unlock Dark Knight...and I had to tell him, sorry you have about 6 patches of story still to get through.

That does not sound like a problem with ARR or the MSQ as such, but rather a problem with the fact that the HW jobs (DRK, MCH, AST) are all locked behind access to Ishgard - which is indeed a problem, but luckily one they have not repeated with the jobs added later on.