Good points.
As noted in the earlier link, breaking down the pelvis does not NEUTRALIZE the attacker, but it profoundly impairs his mobility.
The pelvic shot makes sense for the opponent with knife, club, or bare-handed disparity of force, since taking away his ability to reach you does in fact take away his ability to harm you.
Anchoring him in place also makes it much more likely that you can deliver a brain shot if he is armed with a gun and center chest shots have failed, since his ability to "duck" a weapon pointed at him is dramatically reduced when his grounded body reduces the potential range of movement of his head away from a gun he perceives to be pointed there.
Tailor the tool -- and the tactics -- to the task. The pelvis would not be my first target facing an antagonist armed with a remote control weapon such as a firearm, but it does have its place in the toolbox.