Security is a social contract that is deeply related to the disproportionate exercise of force. The theft of an item worth a few hundred dollars can result in police investigations and legal actions that can reach several hundred thousand dollars. But, to not pursue the action ultimately creates an environment of mistrust and chaos. The use of resources expended to stop a criminal is justified by the threat of future actions.
Architectural features that promote security have a high rate of failure. Walls can be scaled, locks picked, doors kicked in, etc...and a fortress under siege is not a fun place to live. In most instances, transparency and density can create better outcomes. A pile of treasure is safer inside a city than out in the wilderness.