I wouldn't say "pure garbage", just "avoiding problems".
Modified carry firearms are not a problem anymore in criminal trials, but can be pain in civil ones.
I remember California's incident from 1973 when S&W .357 Magnum owner was sued for negligence discharge during vehicle accident. It happened because of "hair trigger".
I'm sure there are more cases like this.
I'm not against modifications, but we have to remember that these days you can be sued for anything, just to get your money...so why risk this?