Poetic (Ironworks) Gear

[Donjo]

The point in your TL;DR was what I was using all of that to really convey.

On the topic of secondary stats themselves, though, I believe secondary stats to not matter at all in the sense that there is no combination of stats that will literally prevent you from being able to complete a piece of content except for too little accuracy or too much wasted accuracy. Going by Role:

Healer: Secondary Stats literally don't matter one iota. Choose your favorite and have fun.
DPS: The difference between the "least optimal" build and the "most optimal" build is a difference of less than 0.02% in overall potential DPS. The only consideration that needs to be made is not to let Speed get too high in relation to long fights.
Tanks: They only slightly matter here for damage, because Tanks have the ability to switch damage increasing secondaries for Parry. I'd figure that you could eke out an extra 4-5% overall DPS at maximum if you switched all Parry for all Damage. An extra 4-5% on low damage which is further reduced by Tank stances.

If you want to increase Tank damage, stack more STR. That's the only way it'll be worth anything noticeable.

[Kuwagami]

snip

I would argue on the significance of secondary stats.

DPS : agree. the average player cannot notice any difference in dps whatever the set is (at comparable ilevels, full left 100 and full right 120 isn't comparable by a iota to the reverse)
Tank: same. Only STR accessories make a noticeable difference. Though a slight increase is still an increase and CAN matter (getting T9's P2 2 seconds faster would help my group having only 4 meteors. even though it is more a dps work here, if I can help in any way I will try to do it)
Healers : That's were we differ. There is a huge difference made by crit. SCH tend to stack it as much as possible to improve adloquium (and succor in a lesser way) and the spell speed bonus from their pet (more likely to happen), it's a bane at high rates for WHM in AoE heavy fights (in T9 at the moment my group's P3 transition is a bit... random due to various avoidable mistakes) so they'll prefer to stack a bit more spell speed in comparison (or even more mana if they feel like it).


Well, of course awesome players will see a noticeable difference, but average joe shouldn't matter that much about secondaries, I'll follow you on that ^^