This is mostly a remnant of their approach to FFXI. By leaving things vague the community usually works together to figure them out. It worked relatively well in FFXI but XIV is a very different game and I'm beginning to wish they would be a little more transparent with some of the game systems.

I will say though that once you know exactly how something works it loses some of what makes it interesting. It's good to keep some things a little uncertain in the mechanics, I just think they need to shift the balance a bit...