This is interesting. I normally purchase my Glocks slightly used. I dont know that I have ever fully stripped one down prior to shooting. I do shoot them prior to carry unlike many people I talk with. Kills me to hear someone talk about their new carry gun and when I ask how it shoots or what ammo it likes they sigh and tell me they have not shot it yet.
This is a concern because many buy and shoot a gun 20-25 rounds and never disassemble or lube or shoot it again. Those are the ones who may see a failure.