Here is my perspective:
I don't generally carry a primary weapon without a holster. The average gun toter never gives it 2 thoughts, but most fights are physical long before bullets go to flyin'
I have had more than a few occasions to end up physically fighting with someone, while armed with a service weapon.
The punchline is that when you are rolling, physically fighting someone, stuff goes flying.
As a weapon retention instructor, I can tell you that this is actually old news.
When you get punched in the face/knocked down, if you have (had) a gun simply tucked in a waist band, odds are more likely than not, it will not still be there.
It is bad enough rolling, bare knuckling it out, but the last thing I want to do is to have to have a brutal ground fight AND be struggling for a loose gun.
I don't think anyone is going to argue that it's more secure, but I don't think it's necessarily that precarious either. Last time I changed the wife's oil I forgot I had the gun in my pants, and I didn't lose it. I wasn't fighting anyone, although from the swearing it might have seemed that way. It's a compromise, like anything else. I also try to avoid going around and getting punched in the face but YMMV
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