Trigger weight is a strange thing. Most people agree that a heavy trigger pull is not good. Light and smooth seems to be the positive consensus. There is a fine line however, between light, and too light. I’ve seen guns with such insane triggers, that staring at them sternly seemed like it would set them off. Having a heavy trigger on your carry gun that feels like you are pulling a sled across a rock bed is not ideal either; but how light is too light.
The answer to this question is going to depend on the type of gun you are using, and its specific purpose. I have a Kahr® that I keep in a pocket holster. It’s the gun I carry when I want to forget I’m carrying a gun. I didn’t modify the trigger at all. I just shot the heck out of the gun, and it held up perfectly, as Kahr pistols are known to do. The trigger is long and smooth, and has a weight of about six pounds. It isn’t crazy heavy, but the distance I have to pull the trigger makes me feel safer keeping in my pocket. It’s true that as long as you handle a gun properly, no reasonably achievable poundage is too little, but I would consider myself slightly clumsy, so I need every edge I can get. If you are not familiar with Kahr pistols, there is no active safety, just a trigger, similar to a Glock in some ways. I am not alone in wanting a heavier trigger either. A shooter I know put his 5.5-pound connector back into his Glock 19, since he preferred not having the ability to bump fire the 3-pound connector by milking the trigger. Without an active safety, I think your chances of a negligent discharge are lower with a heavier, longer trigger. As we all know, negligent discharges make gun owners look bad. When someone accidentally shoots themself in a public setting, it usually makes the news.
In an actual gunfight, the human body tends to react with the fight or flight phenomenon. Much of the blood in your extremities rushes to your vital organs so you can high tail it out of wherever you are. Your fine motor skills reduce themselves to being almost useless. It takes a large amount of training to be able to use fine motor skills when frightened. Aiming your weapon and pulling the trigger is insanely difficult if you haven’t already stored the process into muscle memory. This is why you should practice drawing your carry gun from wherever it is you keep it, shoot, rinse, and repeat. We evolved this little reaction because when we were living in huts, it was a better idea to run from the saber toothed tiger, rather than stay and try to pet it. I guess we didn’t figure we would be trying to manipulate triggers and switches on pocket-sized hunks of metal for protection.
While there is little doubt that a light trigger will help with accuracy, on a carry gun, this can be a double-edged sword. Most defensive situations happen at almost point-blank range, so precision accuracy is not always what you need. A mediocre trigger weight and long pull still goes bang, and the gun will not discharge just because you sneezed.