Final Fantasy games have always been based around the main stories with stuff to do on the sides, there should be no difference with this one, i know many people are coming from other MMO's where they can access expansion stuff as soon as release no matter what they have done, why should this be the same? As for people complaining about doing it on ALT's , i have had a total of 5 characters whom have ALL done the story quests and all side stuff, YES it does get boring, but , i was a fool for having 5 characters in the first place, though each time i did the story i enjoyed it, maybe that is because i have been a Final fantasy fan since FF4, or maybe it's because i hate being handed stuff on a silver platter and i like to earn.
Again i was a fool to have 5 characters, i now stick with one character and don't see the point in ALT's (except 1 for maybe extra chests in Savage, or maybe for playing with friends on a different server) Others you should only have to do MSQ once, and for the people who come to the game for Stormblood as new players, i believe they should do the MSQ like everyone else, it's part of the franchise.