I agree with this, for a slightly different reason. If an instructor opts not to allow someone to use an AIWB (or any other setup) because it's hazardous outside that student's present skillset, I have no issue with that. I do not think it should be banned outright.
The last time I was at CSAT, Paul was telling us about a student in a preceding class who carried a 1911 AIWB, with the safety off. This wasn't something that student just came up with, an "instructor" had actually taught him that. If that student hadn't brought that ridiculous setup to a real trainer, he could have ended up being a statistic.
Trying to teach basic safety manipulation at the same time as teaching a nuanced holstering technique is a lot to ask for any instructor, and Paul rarely supervises more than about six people at a time. So restrict <insert practice here> for individual students if necessary, but people need to have their secondary ignorance exposed, and that's what training is for.
I don't know that it's hate at AIWB, precisely. More annoyance towards tacticool trends people jump on without giving any sort of real thought into what they're doing.
I see your point, but I think you're approaching this from a pragmatic position, rather than the reality of the mess insurance actually is. Have you seen insurance billing codes? There are thousands of them for every permutation imaginable. So when an individual or a company is assessing risk, there's a lot of voodoo behind the scenes I can't even pretend to understand.