I can say this...I routinely bought fresh crystals so that I could get about 800 energy per day to use on keycard battles for cash and droids. Routinely. Per day...to keep up with bringing more characters up to my current level, and to experiment. I didn't mind, that was my play style.
These new event rewards? Not only did they lower the amount of the credits from the event that comes every few days, but the replacement keycard battles are preposterously low, and I will not be re-upping my crystal supply to re-up my energy for these battles as I was before.
The reward is just too insubstantial to make it worth it to me. Leveling will be far too slow now, and ok...so they upped the credit rewards in GW but that's such a slog, and it's own manner of headache.
Honestly...the consistent income I knew I could make from the old event was the driving motivation to keep playing and trying new characters. With that gone and making money now even more of a chore than it was before, I expect it won't be long before I go the way of the OP and find a new game as well.
My 3DS is about to have a few new games out soon anyway. I won't feel nearly as bad about devoting my time to Fire Emblem and Bravely Second over this now.