True it takes maybe an hour or so to get to 15/20 depending on how much you do. With that said though, why not start them at 1? Not to beat a dead horse or bring up "other" sutff, although I am going to. Other MMOs, with expansions have introduced jobs gated behind the expansions. SE specifically has done this in the past. The most well known is XI, Treasures of Aht Urhgan and Wings of the Goddess both had jobs that were gated behind that expansion in that the bestowing NPC's were located in the expansion areas. To get there you traveled through level 40ish areas (IIRC). Once unlocked they followed the start from 1 path.

Now this is not that game nor the same development team, I know. It is though a model they feel is successful.

IMO; DRK, MCH and AST all stem from the new expansion area. They are jobs that are "only" found in Ishgard / Dravanian areas. Please if anyone has any links to provide better insight, that would be greatly helpful.