The thing is: it's very easy to play up the likelihood and severity of problems that are entirely imaginary. This can be just a bad habit, but also a deliberate tactic. In either case, a lot of effort, time, money, etc. is wasted.
Waiting for something to actually happen before allocating resources to preventing it is (to some degree) a rational policy.
The argument there is that waiting for "it" to happen would be way too late. Especially if "it" is a billion people are dead and the rest of the people don't have much time.
Waiting for something to actually happen before allocating resources to preventing it is (to some degree) a rational policy.