Note on concealed versus open carry
I have no problem with people openly carrying their guns, but there are crime deterrent benefits from concealed carry that you definitely don't get from open carry. Here is one example. As Israel has learned the hard way, simply putting armed police and military on the streets didn't stop terrorist attacks. Even if you have openly armed police or military on a bus, the terrorist has the option to either wait for them to leave the scene or to kill them first. With CCW, the attacker doesn't know who is able to defend themselves and he doesn't know whom to attack first.
Take the case of attacking individual victims who are not around other people. Having more people carry concealed generally produces more of an overall crime reducing effect than open carry because criminals will leave the open carry person alone and then wait for someone that is unarmed. Concealed carry people produce a benefit for people other than themselves.
The question here isn't whether open carry doesn't deter crime. The question is which deters crime more: open or concealed carry.
The main reason for carrying openly is to make a public statement, to demonstrate to others that it is legal to carry a gun. That is fine if you want to make a public statement and that is your choice. If you want to reduce crime, while having some people with open carry is fine, having the same percentage of people with concealed carry would have a greater impact.
This point is independent of licensing. Obviously some states such as Arizona, Alaska, 98+ percent of Montana, and Vermont allow concealed carry without a license. Hopefully with a few more states changing their laws to adopt a "Vermont" style approach it will be possible to test how effective in reducing crime.