Well, it is easier to add a manual safety, magazine disconnect safety, or heck, even grip safety than it is to eliminate human error.
Except that it's not an either or situation. Adding all those things doesn't prevent NDs.
The fact is that NDs are most often the result of a person INTENTIONALLY pulling the trigger of a gun (dryfiring) that they believe to be unloaded. There is no safety that will prevent that from resulting in an ND that won't also make the gun useless for its intended purpose.
It is not an either or situation. It is a BOTH situation.
Sorry but people are not dying left and right because they cannot actuate the safety on their firearm. There are plenty of people having NDs, injured and killed because someone violated a rule AND there was not a mechanical safety/intelligent design which acted as a safety net.
I love the twisted logic some of the "Cult of Glock" here toss around... "Glocks are better because a manual safety can fail!" is one of the lines tossed around. Of course when it comes to making the rational statement that people are imperfect and prone to error, meaning a violation of the rules WILL occur from time to time, then it is simply unnaceptable. There are people here who seem to believe a piece of forged and milled steel functioning in a proven design a hundred years old is more likely to be a point of failure than human error... RIGHT!
Sorry, even if an ND only affected the shooter I would never agree that a Glock should be a new or casual shooter's gun. It is like handling a pit viper without gloves or gear, there is nothing but your skill between you and death. Unfortunately NDs also affect many others, from the third parties who are shot to their families. There are too many safety nets missing to make the Glock a safe weapon to entrust to a new or casual shooter.
1. Auto (meaning the famous "hidden round" when the mag is dropped)
2. No Manual Safety
3. Shorter and lighter pull than a DA revolver (a problem due to #2)
4. No Magazine Disconnect Safety. (Sorry but we all KNOW of plenty of NDs where some person dropped the mag and thought it empty FLAME ON!!!- See #1)
5. Design requires the trigger be pulled to disassemble!!! (In the running for Dumbest design feature EVER.)
Sorry but a casual/new shooter handling a Glock is like a garbage man handling plutonium.
For those who continue to attest the gun has nothing to do with safety as long as it mechanically functions properly how about this question:
Which car would you allow a your 16 year old son who just passed his road test to have for his personal use (money being no object)... a Ferrari or a Honda Civic? The Honda is obviously the SAFER car for the new 16 year old driver, just like the Glock is NOT the safer gun for the new or casual shooter to own.
Nobody is saying the Ferrari is not mechanically perfect, nor that it does not do everything it is supposed to do. We only know that cars, like guns, are designed to fill a function and fit a need. The needs of the casual/new shooter are not simply a gun that goes bang every time you pull the trigger but one that is easy to operate and compensates for the shooter's weaknesses. Anyone who does not admit that people are fallible is fooling themselves and utterly full of it. You would not believe the 16 year old kid with a liscense so new it smells from being laminated that he can handle the Ferrari nor should we believe anyone who is less than 100% committed to firearms handling with real experience should own a Glock (or other similar psitol with its list of less than desirable features for a new shooter.)