You are open carrying, say in a park, walking your new puppy. Strangers approach to pet the dog and ask directions. They look nice, so you watch them, but let them approach. Who does not want to pet a puppy? In a split second, their real motive for walking up to you is known. They just robbed a bank, and the bag they have is bank cash. They have one gun, and two robbers looking to carjack a ride. They were looking for a car, when they spotted your gun on your hip. One robber with a concealled gun, being bold, walks up asking to pet your puppy, and ask you where the bus stop is. When you raise your hand to point to the bus stop, the robber takes his gun, and plants a bullet in your temple. Killing you instantly. The other guy grabs your gun, and now they have two guns, and walk on, still looking for a vehicle.
If you had your weapon concealed, your puppy would still have a best friend.