I'm for CC licensing and have one myself. Here's some of the reasoning:

1). Carrying my handgun openly advertises it to those who might want to steal it. If a thief/robber wishes to come up on me to get it, with any brains in planning and approach he most likely he will have the advantage of surprise intent and advancement. My handgun offers no protection if a guy comes up and pulls out a gun and says "give it to me." He has the draw on me already so all I wind up doing is giving him my gun, and now it's a stolen weapon on the street in the hands of criminals.

2). An open gun signals that I might also have a lot of cash on me, making me an extra attractive target besides the gun.

3). A criminal who got the draw on me might not wish to let me go after a theft and if he doesn't know I have it then I have a chance.

4). A concealed weapon with a person who already has the draw on you has a greater chance of not being stolen because he may not know you have it.

5). I don't want to make nervous ordinary citizens or trigger off any hotheads, thugs and idiots who see it.

6). It's unsightly to my regular clothes of the day to carry openly.

7). A concealed weapon is harder to drop or otherwise misplace or forget.

8). If someone has criminal intents with a gun and/or are prohibited owners/carriers, they possess and conceal it anyway, so the CC licence to lawful owners with valid purposes does not encourage criminal activity.