I think the law is more because some people accidentally had a gun exposed and got arrested for open carry. At least that's what I heard. Just doesn't make sense that carrying a gun concealed is OK (with a permit) yet that same person could be arrested if the gun becomes exposed.
Of course, I'll bet the anti-gunners are popping blood veins in their heads over this one as well. Claiming that Florida will become the WILD WEST or something because people will go berserk if they can carry a gun openly on their hip.