There are many of us who take a new class as a new chance to re-experience a game.. from the start to the finish. Those who are already adept at the game can swiftly level a new job in no time flat - XP bonuses, fates, leves, etc., it doesn't take long if your goal is to do it as fast as possibly possible! For that reason I ask that you allow those of us who would prefer to take it slow and work their way back through many of the quests we had already experienced and re-immerse ourselves in the story to play the new jobs from first level and on, after they are unlocked. I have no issue with unlocking at all, quite the opposite! But I do want the chance to work my way through Eorzea again so that I can re-experience much of it, rather than being forced to skip partway through on a new class.

Just my opinion, in any case, as I have always loved the opportunity of a new class to bring a new start to a game I already love.