Sorry to be the debbedowner, but this is their current stance on the card system
http://forum.square-enix.com/ffxiv/threads/402453
(00:29:01)
Q: Thanks for the adjustments made towards astrologian! Both the controllability and heal potency has increased and it feels much better. Do you have any plans to add new effects to the cards?
A: We are truly sorry about the initial issues with the feel of the job that resulted from various adjustments to reduce its party synergy.
Regarding card effects, they were changed to their current iteration because we received feedback from all regions that players did not want "useless cards." While the current iteration does indeed reduce the excitement of drawing a "good card", if we were to add various different card effects, then we would just return to fishing for the most favorable one, so we decided to simplify it.
We plan on continuing with the current iteration for now
I would gladly take Old AST's card system with all its faults if i could but this is something we probably won't see again until 6.0 at the earliest. Keep asking for it maybe they'll change it for 6.0 but right now we need ways to deal with current AST too since we have nearly 2 years of it to deal with.