I understand your sentiments, but I don't believe we should force people to get their job crystal if they do not wish to. That being said, there should be much more to make players aware of the fact that there is a job crystal if they do not know it exsits, and help guide them to where they need to start. I simply believe a lot of people just miss that there is a job crystal quest path after you finish your lvl 30 class quests, and simply just miss out. Anyways, the tl;dr is this, Don't make it mandatory, but we need to find ways to make it apparent and obvious to people that there is a job quest at lvl 30 to upgrade your class.