The way levels of security are decided is by balancing the need for security and the need for access. We decide how much security we can handle before it becomes too much of a problem. We may have two locks and a key card reader on an office door, but if I decide that using the key to turn both bolts is annoying and what is on the other side of the door is not that important then I’ll just use the key card reader because the need for security is not as great as my need for convenient access.
