I can't do a thoroughly thought out post right now because mobile limitations (but I will come back to this thread later and write out my thoughts to things), but the fact that you can outright fail Yojimbo's coin mechanic and only take 16,000 damage means that the mechanic is poorly designed.

It doesn't teach players to execute it correctly; it teaches them: "I can completely ignore this mechanic and suffer very little for it". Such a mindset is not good to have, because then people go into Savage or Extremes or even the 24-mans with this mindset of "I don't have to actually execute mechanics because they don't punish me for failing". Then, naturally after they fail a mechanic, they whine about the content "is too hard" and should be brought down.

I had more HP in Heavensward than Yojimbo's coin mechanic does to me at level 70 in full 290 gear. I shouldn't feel more challenged by the bosses in Doma Castle or Bardam's Mettle or even Aurum Vale than supposed "expert dungeon" bosses. When a DPS can reliably tank the bosses in "expert dungeons", there's an issue there.