Logically, adding in the frequency works - I totally agree. In reality, though, people don't understand frequency and how it applies to them which is why we get into these security theater situations in the first place.
>people don't understand frequency and how it applies to them
Or perhaps they do. Frequency works when assessing statistical risk for a population. Statistics work for populations not for individual instances. The fact that my chances of being attacked by a dog are statistically low are little solace when faced with a frothing mad pitbull.
Ultimately individuals want to preserve themselves (and family/friends) not simply preserve a high proportion of the population.