Lazy speculation is lazy; it's entirely possible the people we got the Jobs from had their own "Relic Quest" that each of them (like Jehantel, Solkzagyl, and others) completed. For all we know, there could be a legend tapestry (think Wind Waker opening) in the Sultansworn areas that describes or shows the Curtana and that inspired Solkzagyl to it where others wouldn't have cared. Or, only as a free paladin was he able to go searching for the clues to it.