I've replaced backstabbed receptacles where the conductor was blackened at the backstab entry. Also some where the body of the receptacle was compromised and the wire was not held in place.
So what you are saying is you have replaced some bad receptacles that were either overloaded or improperly installed but you are blaming the wiring method for the problem?
There is a fact that cannot be disputed. UL test the method and puts their mark on the method. This means there is nothing wrong with the method unless someone thinks that their experience is far superior to the vast knowledge of the testing lab.
Someone finding a device that has failed because of misuse or improper installation does not mean the method being used is not good it only means that the person making the repair lacks the education to know the facts and lacks the ability to discern the problem.
In my years of electrical work I have found wires on the terminals of panels that were blackened and the screws welded to the point of not turning so I suppose that a screw terminal is an inferior method of terminating a conductor in a panel. Just maybe these failures were due to improper installation or even overload.
In my years of electrical work I have found receptacles that had less than one ounce of tension on the slot blades so I suppose that these receptacles were inferior because they wouldn’t hold a cord cap in place. Most of the receptacles I found in this shape were in medical establishments. Maybe it was the fact that the electrician was a hack, who knows? I do! It was due to the device being overloaded not a failure is the method of installation.
When it comes to failures in these receptacles in a dwelling unit, and this is where you will find the stab-loc method of installation, the failure is sometimes due to an improper installation but in most cases it is due to an overload on the device by appliances such as portable electric heaters, vacuum cleaners, blow dryers and the like not the method of installation.
The method of terminating the conductor does not change the fact that any 15 amp receptacle is only tested to 12 amps continuous current for a period of three hours. This device is listed for a load of only 12 amps and the method of terminating the conductors does not change this rating.
Once electricians have the number of years of experience that I have and if they continue to study current flow as I have by attending the many seminars that I attend each year and listen and learn by those who have the responsibility of testing these devices they learn to find the cause of the failure not just blindly running around pointing to some method and calling the person who made the installation a hack.
Over the years I have found just as many failures on receptacles that had either the conductor wrapped around the screw of a pressure plate that secured the conductor as I have using the stab-loc method maybe even more. Of course I have worked in many different levels of electrical and I am not limited to just slinging rope through 2 by 4s. I have many more years of industrial and commercial than residential and these receptacles don’t use the stab-loc like residential ones does. I think maybe that through this experience that it was something different than the stab-loc that caused the failure, maybe it was the load imposed on the device that caused the failure or improper installation methods.
My granddaddy once told me to look before I jumped into the water unless I was certain of the depth of the water I was jumping into. Using this theory I would say it would be wise for a young electrician to look at the reason of the failure before just pointing to the method being used.