i think that when u try to think of what exactly is role playing , u come to a conclusion that it is taking part of a virtual world, where every character has its place, and its trying to find its place in the world..
the world is built, of these characters who try to take place in it, and thereby creating this world.
a job, much like other factors of this game that are planned to be implented are a part of the charitasritic and way the character (player) acts..
it helps the player to feel more with the character and makes his able to stylzie the character the best way he feels to,
this leads to characters that are closer to humans in real life, increasing the realisem of the game in total
besides, why cant roleplaying be a part of your job too?
u can have quests that have to do with your job, places where u can go, etc..