As others have said, context is everything. A lot of these ready positions are frankly being used, or even taught, totally out of context. I've never personally seen Ken's version of the Temple Index, using both hands....and it isn't something I think I'd be likely to use moving through a panicked crowd in the proverbial "Active Shooter " situation. On the other hand, though I haven't taken the VCQB course from Centrifuge, I xlcan definitely see the context and value in their version of TI...in context. Instagram hissy fits aside.
We have unit's in our department teaching Sul in really inappropriate contexts, in my opinion.....basically as the "one true ready.position". Then I see body camera footage of cops breaking the plane through a doorway turning toward the unknown alone....with one hand on the gun with a bent wrist. Not ideal and not in context. There's that word again. Think @TGS used it earlier? Maybe those Discount Security guys know something after all. You do get more for less!
On the other hand, I do agree with Ken of the "Holster Index" being a very under rated and under used concept. Especially in the context of running around with a gun.