Personally think it's fine, but I enjoy fates. Made like 10mil selling gemstone tickets doing it. Saw a lot of people getting the gemstone vendor unlock achievements.

Two thoughts really:
They should have required 6 from each zone and doubled the drop rate. Same time-investment, just makes the drops a little more consistent to get.
Should be able to buy the follow-up tomestone rocks while gathering them. There was an annoying pressure to get the fate-thing done fast, to keep from wasting/capping on tomestones.