Why did SE decide to make the three new classes not require base classes?

[Felis]

Much like Ninja is awkward with the fact that it can take cross-class skills, but doesn't share any of its own with other classes/jobs. If they keep going with that, every new Job will rely on the old cross-class skills from the old Classes, which will get boring really fast.

The jobs with no classes can maybe not equip any cross-class skill, because no class will used as sub class. Also every skill of the new jobs would be 100% jobskills and therefore not equipable with other class/job.

Also new cross-class skills come with level cap raise (I hope). The old classes would still learn new skills and I really hope that they would be not all exclusive skills..