We have to remember, the bears have learned how to open doors and they do so. They go from house to house until they find an open one and then they go inside.
I have a neighbor who learned the hard way that he should draw the drapes so that passing bears cannot see the refrigerator. The bears have learned that they often contain food.
My neighbor had his doors locked and the lock suffered no damage. The bear completely destroyed the door into his screened porch and the door into his home and made a mess of the place. The door lock was unharmed.
Security at my place consists of armed residents and vigilant neighbors. I almost literally live in a glass house and the glass doors would yield to a rock in seconds. I don't wish to change things so that I live in a cage.