It definitely should not be mandatory. It's good having the option to not do them.

Not everyone intends to use a job class and not everyone intends to level them beyond what is needed.
For one firsthand example; In my community of housing builders, we do not unlock jobs because it is a waste of time for an alt who is never going to do any content past hitting the mandatory 50 requirement

Make a forced tutorial window pop up at level 30 or whatever, but there is no need to force peoples hand because some minority group just didn't know