Why Eureka is a worse form of the Diadem IMO

[Reynhart]

So yes, you are right. The game choose to not punish you for being bad, and you see this as a problem. Which is...exactly my point, no?

This is a problem, but it's not a problem of Eureka but a problem of the whole game. In fact, like Kaldea nterestingly said, wether you do top DPS or completely suck at it, you'll get the same reward in raids, while in Eureka, doing the train underleved will give way less reward that targeting appropriate monsters. So Eureka is the less guilty content of FFXIV regarding this.

A game need to punish players when they are playing wrong, in order to get a better feeling of achievement when they are doing it right.

That's a very debatable philosophy and the main difference between XI and XIV "Do you punish those that do wrong or do you reward more those that do right ?" And again, Eureka, for at least having an Xp loss and a level down, is the content that lean the most toward the former (In the context of FFXIV).
I personally wouldn't be opposed to losing some Xp even if you're raised, that would make people pay more attention...Yet again, they chose to add objectives in Eureka to give more incentive to killing monsters, following again the philosophy of "better rewards by doing better" instead of "no reward for doing bad".

But I'm saying that Eureka could, and should, have a more interesting means to farm, have a better loot table outside of 2 poor items. I'm okay with the relics being inside Eureka. Or that Eureka itself is not hard.

Frankly after the fiasco of both Diadems, I undertstand how they didn't want to go deeper into Eureka before seeing if people would follow it. And I like Anemos even only for being something different than the dungeons or raids, and for making people actually talk to each other, organize (If only a little) as a group, and generally be helpful. I hope that Pagos will improve this whole concept.