I'm not an expert on this,I could be wrong.And I'm too lazy,right at the moment,to drag out my Gray"s Anatomy.
But I don't think its true the pelvis is not a "stopping" target.Having said that,I don't question shooting center of mass in most cases,or high torso.
But if the pelvic zone is the target you have,take it.Like if your arms are pinned but you clear your holster or? any situation that occurs.
Have you ever "hip shot" a 12 ga by resting the gun butt approximately below your appendix? Not more than once!!
Suppose you pick as an aim point the location of the femoral pulse checking point.I think its called the "femoral sinus" The femoral artery is there,of course.Also the femoral nerve.Handgun temporary cavitation may not rip the tissue,but it does impact .I'm thinking neural control of the leg is lost,at least temporarily.If you are standing on two feet,you hit the floor.Maybe with a femoral bleed.If I'm on the floor and all I have to shoot at is the ankle of an active shooter,..If I shoot he may fall down.Then I have a head shot.
I know from experience the trochanter area,the ball on the femur,where it fits in the pelvis,that area is tough to ignore when hurt.That would be a good hit.
With reasonable penetration,the sciatic nerve is another pevic target.That will kill the leg.I have felt what seemed like a lightning bolt through mine,without being shot.If you are a little high,you get kidney.Rex Applegate suggested the Farbairn to the kidney as instantly debilitating.
The sacrum/illium area has a lot of major nerves,the "cauda equine" I think.And bone impact transmits to the spine. The abdominal aorta and vena cava (sp?) are major bleeders. Midline,from the tailbone up you will have neural impact,along with ortho damage.
I have not been in a gunfight or near a gunshot victim,but the novel/Hollywood story is "gutshot" people suffer terribly.I have been punched.
I'm not suggesting "I'm trendy and cool,I do pelvic shots". But it would seem to me,if you can get a pelvic hit 1/2 second before you can acquire another zone,or belly to belly as you clear leather,pull the trigger on the way to the torso or head shot.
There is a lot of debilitating anatomy in the pelvic area.