The OP's question is a good one. He just wants input, because he is not sure whether or not it is a good idea. How we answer the question determines the course of the thread.
In most places in the continental US, a weapon is not needed to protect yourself from animals, with the possible exception that bear spray in Grizzly country could be helpful, but that does not guarantee your safety. A hand gun will probably not be effective if you are attacked by a bear or mountain lion... it will happen so quickly, you will probably just p*ss off the animal -- if you have time to get a shot off.
You need to be one heck of a marksman to quickly pull a weapon and hit a snake with one shot, if you stumble into striking distance. A hiking pole is more effective. If you are not close enough to a snake to get bitten, it is not a threat to you. This should answer the OP's questions.
I have been backpacking for a long time too. And with a couple exceptions don't even take a GPS or a cell phone. I have never carried or felt the need for a gun, mp3 player, or PLB when backpacking. To me they are all the same; just extra weight. If you need them for some reason, then bring them. Many people never have a need for any of them, others need them all.
I was in the military and was expert in the use firearms and some other nasty stuff for their intended purpose. I don't hunt, but it is not because I am against hunting, it is just something I am not interested in... I am not against guns. And yes we have the right to have them, and I would not want to abridge that right.
This topic comes up every so often, and it is a debate that no one can win, and it usually gets quite heated.
Over the decades a lot of people have asked me if I take a gun, and most of those who ask do not hike. Most people I know who backpack do not take one, and a couple tell me they do. Some beginning backpackers have expressed concern to me about running into bad people. And it was mentioned earlier in the thread. Like anything else in life, I suppose there is a remote chance. So if you decide you need a weapon, think about it carefully. If you were looking someone in the eye, could you really pull the trigger? You may think so; but could you?
Many rookie law enforcement officers and Army privates cannot do it, and they are trained to kill if needed. Some of the the ex-cops and ex-military people here can or have pulled it; but DO NOT assume you can. If you show a weapon you better be darn sure you are willing to use it, any hesitation to pull the trigger could get yourself killed. Just talking might get you out of a potentially dangerous situation whereas a gun might escalate a confrontation with deadly consequences for somebody. A life threatening confrontation in the wilderness is more than likely not going to happen in the first place. And if you run into really bad people, they are probably going to be better armed than you to begin with.
So if you absolutely must take a weapon, phone, etc. then take it. It is up to you. I don't think you need a weapon, but it is not up to me to decide what is best for you.
BTW, I have take trips where my big 3 weigh around 20 ounces :)