Currently, classes are pretty much pointless. There's rarely a good reason to play as a class rather than as a job - even in pre-30 content where the level sync bars you from using any job abilities (and nerfs the number of cross-class skills you can use!), the raw stats you get from the soul gem still typically meant it was better to participate as the job rather than the class.

That said, it was my hope that SE would FIX these issues - that they would make classes viable again. It was possible, whether it be through specialized gear or class-only job abilities. They could have turned it around. The Dark Knight announcement has pretty much dashed these hopes. SE has effectively thrown up their hands and admitted that they lack the creativity or dedication to fix what is broken, and so are tossing it in the trash instead, along with any future hopes of interesting multi-job options for classes (SMN/SCH will likely remain the only such instance).

This was disappointing, but not surprising. By the same token, I very much doubt that the class system that exists will be removed, as that, too, would require creativity or dedication. It's easier to just leave it, a dangling, useless appendix on the game, than it would be to cut it out - so that is what they will do, the easier option.