Well most people aren’t willing to train on their own, much less pay for a class, pay for travel to get there, pay for ammo, and *gasp* take the big ego hit of showing up and finding out that they suck at shooting a pistol.
Most will never even invest in a good belt and a good holster. A holster with good pull from the top loops, clips, or other belt attachment, that is also rigid and well made costs more than $30. So they won’t buy one. Good gun belts also cost more than $30 so they won’t buy one of those either. Thus they’re convinced that it is impossible to carry anything larger than a .380 or a J Frame (that they never train with ever) comfortably. They’ll also do questionable things like carry a semiautomatic pistol with no round in the chamber, because the Israelis do it. Never mind that Israeli tier 1 units carry in condition 1, and only the poorly trained conscripts carry a pistol with no round in the chamber.
So for that 95% of pistol shooters/carriers AIWB is probably a horrible idea. They’re not going to be consistently able to administratively handle a pistol in a way that prevents ND’s into their crotch area while holstering the pistol into their garbage $30 bargain bin holster that isn’t rigid enough to stay open at the top. Most will still avoid ventilation of their genitals because modern pistols are chock full of passive safeties, but some will not be so lucky. So they shouldn’t carry AIWB.... they probably should not carry a gun at all but that’s another argument for another day.
I’m probably going to start carrying AIWB since I prefer carrying larger pistols and AIWB is more comfortable with a larger pistol than strong side carry on or behind my hip. I’ll either continue to carry the VP9, or acquire a hammer fired pistol of some description to do this. A hammer fired gun gives me more control over the firing mechanism when holstering, which is more of a range/class/training advantage where frequent drawing and reholstering is a thing. Day to day it will be insert magazine, run slide, press check to confirm round in chamber, drop magazine, top off magazine, re-seat magazine, place pistol in holster, place holster in pants at 1:00 position, attach loops or clips to belt, secure any other daily carry items; then carry out the rest of my day.