I know my first reply was just a joke, but I’m gonna actually try and contribute to the discussion now.
While yes, some people prefer survivability over damage, most active players nowadays play in discord raids. In those raids, DPS items are the most important, as they are key mechanics in endgame dungeons, such as Voids or Oryxs’ Sanctuaries. If the group can DPS down the boss before you can tank damage, then why prioritize tankiness?
You are right in partial regard, however, as @Seelpit said, some classes don’t benefit as much from MP increase, examples such as the Warrior or Paladin, which give buffs. Since their buffs last for a while and aren’t just a short burst of an effect, they can regenerate their MP before they need to use their ability again, especially with pets.
Like you did mention, some people prefer defensive stats. Ironically, this usually excludes DEF, since the base 25 DEF most classes have, along with the decent amount of DEF the armors already give, are serviceable. DEF has diminish returns, as you need more and more DEF to take less damage from a shot. There’s even a point where more DEF doesn’t lessen the amount of damage. You said:
The reason the Ring of Decades (or Forgotten Ring if you’re different) is valued is because it specifically gives a lot of HP, not because it gives defensive stats in general. In contrast to DEF, HP has no decline, so more of it is never bad. You also never mentioned the Ring of Unbound Defense, which sort of feels like you cherry picked your evidence, but I digress. Anyways, people choose the high HP ring over the high DEF ring because DEF has a decline in amount, while HP is just always good.
Let’s take this back to the actual question. Crown and Coro both give the same amount of HP, but Crown gives more DPS stats, while Coro gives more MP and DEF. MP is mostly negligible since pets are so powerful, along with the fact that some classes don’t benefit much from an MP increase. DEF can also be traded off since the base DEF for classes and DEF from normal tiered gear is considered fine. I didn’t address this part however, so I will now. Coro gives a high DEX increase, while Crown gives more of a balanced DPS boost, to both ATT and DEX. The reason Crown is considered possibly better in terms of DPS is because it’s more balanced. It has both DPS stats, and is therefore more applicable to classes in general. Meanwhile, Coro gives a DEX boost, which is more situational and only benefitted from low DEX classes. You’d only use a Coro on classes like Knight or Samurai, but you could use Crown on any class and it’d be considered a great option.
Lastly, why did you compare Divine Coronation to The Forgotten Crown instead of the Bracer of the Guardian? Feels weird for you to bring up one item against the original then compare a different item entirely. Some of these arguments are taken from other repliers here, I just wanted to present all the evidence for my argument against yours.