It is, but it is also true. You are comparing junk IWB holsters, used by poorly trained people, to quality aiwb holsters, used by some spectrum of people, presumably.
Also, the twigs and berries are not the big concern to most people I talk to. It is the femoral.
Most strong side, self inflicted wounds seem to be of the lower leg, or at most, the upper leg. I'm unaware of any that traversed the body. I'm not saying it hasn't happened, but I've heard of tons of leg injuries, and seen a few strong side ND's, both with and without injury. I've yet to hear of anything worse.
Stupid people are unsafe with anything. Well trained people are pretty safe with anything. The problem is, well trained people sometimes act like stupid people too.
For the USPSA matches I run at the NRA HQ Range, I'm using USPSA rule 5.2.6 to ban any holster that requires the shooter's trigger finger to deactivate a retention mechanism.