Classes are not abandoned.
Did you play FFXIV after the jobs were implemented? ... WTF is THM?! BLM or GTFO!

Classes give you more flexibility because you can combine the abilities of more other classes.
Yes, I know.

There aren't going to be new restrictions like "jobs cant do this but classes can".
Why not? THM can AoE sanguine rite with CNJ's sacred prism ability. I would like to see more abilities used somewhat like that in ARR.

You class is not "abandoned" when you're using the job. The class is like a foundation, upon which the job is built.
touché