I remember a while back you could choose to start as a courtier. Now it requires 21 days in realm. Why?
It's easier to become a priest. Priests are a lot more powerful than courtiers in my experience. Also it's impossible to eject a priest from a religion. There has always been a lot of potential for people to easily infiltrate religions and be impossible to remove.
So with that in mind why are courtiers such a privileged class. Is it concern that too many people will play as them thus undermining the war and combat nature of battlemaster? I doubt that will happen. It's rare for there to be more than a couple courtiers in a given realm.