As a fairly new player, I really don't see the big deal with this. I will complete the story up to 50 and play the game that I purchased. Games have always had classes that had prerequisites, such as the Death Knight in WoW or any of the single players games that unlock additional characters upon defeating the game the first time. There's plenty of jobs for new players to choose from atm, having those three gated behind the story is good, imo. It gives new players something to look forward to.