1. ATMA stone drop rates are completely random in that not every fate grants one, and the person getting it when it does drop is completely random as well. So, someone who has done every fate in the zone and got gold (some people are not getting gold and I don't think they realize that they had zero chance when that occurs) 8-10 times are still waiting for a drop, and someone zones in, joins their group, and gets it on the first fate, because RNG is random!

Possible resolutions: Tie it to completing every fate in a zone with gold even the rare spawn fates; Keep the fate that drops one random but give it to the highest contributor of that fate; Tie it to the completion of 100 fates in a zone with gold.