The cold, hard cynic in me says the low exp from FATEs was entirely intentional, including plans to increase it at a later date, they just wanted to artificially slow everyone down to drag out the 50-60 grind at first and ease it later.
Them listening to people about FATE exp is just part of the plan they already had, they knew it was low and knew people would complain, and they knew they'd increase it to ease the process later.
There's a reason why the exp amounts still haven't been fixed 2-3 maintenances after they acknowledged it as an issue.
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