Why do so many people get nervous when they see a gun owner open carry in America?

The question was asked on Quora, and here is an interesting answer by Matthew Franklin:

I’m a combat veteran. I spent 5 years constantly around many different weapons systems, from pistols to munitions that would reduce the human corpus to the stuff you find after the lunch rush on your typical McDonald’s grill. I have conducted just about every aspect of human behavior within reach of a firearm. I am a supporter of the Second Amendment, and own firearms as a civilian. And I can’t stand open carry.

I totally own that it may be due to my two combat tours in Afghanistan and Iraq. I mean, if there’s any place where open carry would be okay, it would be those two disaster zones. But I guess that’s the point. If you’re in the United States, unless you’re in the middle of a serious emergency, you shouldn’t need to have a firearm ready to shoot someone. If it’s a handgun, it should be holstered and concealed. If it’s a rifle or shotgun…why?

Most Open Carry advocates hold forth as if the United States was some Third World war zone, or banana republic where lethal force is the only thing guaranteeing your ability to live a normal life, which is just bullshit. I’ve been to the deep, dark, asshole of the earth, and it doesn’t look like Round Rock, Texas.

I believe a good part of the Open Carry movement is plain old, out-and-out wish-fulfillment fantasizing, and it’s kind of disgusting if you think about it—they wantsomething terrible to happen so they get to kill someone else. If you’ve ever been in a reallethal force situation, you understand immediately how perverse and disturbed that is.

Another alternative is that they want to use their possession and open carry of weapons as a tool to subconsciously intimidate others on a psychological level. This is just juvenile.

The last reason I could see someone doing this is if they’re actually truly afraid for their lives going about their everyday business. In which case, I truly feel for them.

The point is, someone who is open carrying is behaving in an irrational manner with a tool of lethal force. That scares people.