tbryanh wrote:You need to be safe from the gun, and you need the gun to make you safe.
1. To be safe from the gun, you need to avoid accidental and negligent discharges.
2. For the gun to make you safe, it needs to fire when you pull the trigger.
Thumb safeties can be excellent when it comes to 1, but they can cause problems when it comes to 2.
If you ever need to fire your weapon in self defence, chances are your going to be nervous and jittery with an overdose of adrenalin pumping through your system. You might pull the trigger without taking the safety off first, and when the gun doesn't fire, your mind might freeze up for a split second making you unable to figure out what the problem is in time to protect yourself.
This might sound far fetched, but its not. While I have not been in any gunfights, I have driven a car for many decades. On a few occasions when I tried to stop the car, I hit the gas pedal instead of the brake. I knew there was a problem, but I didn't know what the cause of the problem was. My foot was stuck to the gas pedal, and my mind froze up for a split second. Luckily my mind snapped out of it in time to move my foot to the brake and stop the car. Similar things can happen when deploying guns that have thumb safeties.
If the gun doesn't fire when you pull the trigger, the gun is not a safe gun.
We obviously have different understandings as to what a safety on a gun is designed for.