You wouldn't say the same about a deadbeat teenager who smashes a car window and grabs someone's purse. "It's not because they're criminal masterminds, it's because of poor car defense."

Locks, physical and mathematical, are for the deterrence and convenience of the generally honest. Law enforcement, as an active defense, is for the deterrence of the actively attacking. At some point you're always going to have to stop turtling and build an army.