If it's true that the quests to unlock the new jobs are in Ishgard proper, I have to agree that it's a quastionable decision. Imagine yourself in the position of a new player seeing all the news about Heavenward. They see the new jobs and go "Those look cool! I think I'll just buy this game." Then they log in for the first time and find out that they need to do a crap load of quests just to unlock them.

I think it's possible that although the new jobs are in an expansion zone, they aren't in the city itself. Not sure about the details that they have given, but I think they only said that you need to the main storyline to get into Ishgard, I don't think they said that you need to do it to enter any of the new expansion zones.