So obviously they have chosen a direction here and have no clue what to do with these base jobs. That is why you can just start Dark Knight at lvl 30, Samurai...red mage for example. Also Reaper will start at 70 with no base job requirement. My honest guess is they think it is working fine as it and do not want to create what is effectively 4 more jobs that they have to balance around.

I mean they have already thrown job quest in the trash can after 70 going forward as a poorly informed design decision opting to go with generic boring role Archetype quest for the future.