Quote Originally Posted by bass9020 View Post
Look at Rogue nothing they have can be used by other classes or jobs.
Actually, they do have cross class skills other "classes" can use. Just nothing for other jobs.

The main reason why they aren't gonna make new classes is because they didn't find it valuable. Class branching means that both jobs will share all but 5-6 abilities up to 50, thus sharing a very similar playstyle and identity, whereas making the jobs from scratch allows them to all have their own unique animations, skills and potencies. Moreover, you won't need to hoard keepers hymns if you want to play both jobs efficiently if they have different main stats.