I don't think so, Edge. It's talk about game mechanics and theory. Tankspot may have the majority of the discussion about tanks and their dps offspecs, but there's plenty of discussion here about dps and healing as well. This seems like it would fit into that mold to me.
It very much depends on the level of your play, I guess. In a casualcore guild like mine, we do not force people into specs (but we do fill raiding spots for synergy) and we run without the 5% crit buff most of the time - people tend to spec for highest personal DPS and it works fine. 3% from pallies (most of our pally tanks take Heart of the Crusader) make up for some of it, though.
In a hardcore situation it's of course tailored to fight, composition and such, but if all else is equal and the DPS lost/gained is a zero-sum game, it boils down to Scorch having a faster cast time (IE a potential higher amount of debuffed targets in the same time), so a short, blunt pigeonholed solution would be to use fire or FFB mages for multi-target fights and a walrus* of appropriate spec (I've heard that affliction is overtaking destro as the prime raid spec, but I dunno) for single-target fights, since it's part of their normal weave.
* I'm a mage and therefore need to put warlocks down at every possible opportunity. Go read Arcane Brilliance, lol.