How would an optional, official parser be toxic?

[Shurrikhan]

We talk about regular runs in trials and dungeons, not the top raiding. Runs where people don't use aggro dumps or Diversion. Runs where people suck evading telegraphs.

That's not casual content. That's just rudely negligent or encumbered play.

Runs where I use Clemency on myself in tank stance while the White Mage/AST can continue to nuke with Holy/Gravity, since my 110 potency spin attack is nothing compared to that.

That's just optimal. You'd need HG (or other cooldowns sufficient to require no healing) and a NIN in a short burst of AoE to outperform that option with SwO-TE spam.

But Paladin is the outlier in AoE. Both other tanks are hamstrung in their AoE by using tank stance. DRK without tank stance can spam 250 potency per GCD for as long as Del-BW will take him when fighting 12+ mobs, and the sure mana gains that allows can outsustain its tank form via DA-AD. The point still stands: one should be ready to drop tank stance when it is effective to do so (which is most, but not all, of the time). Else they risk making things harder on the party.

I can tell you're not holding your party back at all due to SwO/ShO usage, but as a guideline, seeing as not all tanks will be PLDs, I have to agree with Melichoir's advice, especially as it was posed in reply to "being uncomfortable with stance-dancing". That excuse, inherently, should be transient. One might not comfortable with it... yet. And it's better for one to stay alive for that first normal raid than to get one-shot and let the lead DPS be taken out, too, in the moments thereafter. But, anything more definitive than "yet" is intentionally siphoning effort from one's party to diminish what's immediately and visibly required of oneself (the MT).