Please to be assured I do not wish to offend.
I grew up shooting hard kicking magnum revolvers and in we learned - taught ourselves really, to "lock down" the firing hand with the support hand.
I realize that gun writers and other "experts" have taken credit over the years for this hold or that hold, however I believe the "natural" hold is the one a user will adopt even under stress-fire conditions.
What I meant by the support hand being outside the shooting hand referes primarily to the support thumb "locking down" the shooting thumb. With powerful revolvers this is a must and in my years of semiauto shooting I've not seen any reason not to continue the practice.
When I hold, my shooting thumb is bent down and my off-hand thumb is locked down on top of my shooting thumb. My shooting hand is "relaxed" while my support hand is "taut"...which provides excellent support against recoil yet allows a fine..."finesse" trigger control.
I have tried to grasp the rationale behind having the shooting thumb stuck up in the air, or jutting forward with no real grip on the handgun, and I cannot find it.
What I meant by "populist"was simply the trend for shooters to jump on the bandwagon of the next big thing rather than think for themselves what is valid by "evidence based practice." I KNOW my grip is solid and allows me to shoot fast and accurately. I have also trained for years to use my support hand to perform the functions of mag release and slide release....notwithstanding "competition" shooters behaviors, and my own real life experience indicates much of what is done on the competition range is useless in the real world...but this is based on MY experience.
I have shot the 1911 for many years...a hard kicking pistol that demands a firm hand and strong wrist for combat shooting, but this is very, VERY different than range shooting. Also, when one transitions to SINGLE handed shooting, having the thumb aligned "forward" means loss of grip and control. As I said originally, I do not mean to offend anyone, but in real life, single-handed fire is VERY common, expecially when one is forced to run, draw, and fire, and in that regard the shooting hand should be "trained" to grip the pistol firmly. I have not found the Glock G20SF to be any less of a "handfull" when it comes to bringing the pistol into action...thus I maintain the shooting hand should be "trained" to with a thumb bent, solid grip...IF the support hand finds its way to link up, great.
Again, this is based on my life exprience for what its worth.