Trying to rationalize all your actions is doomed to failure. You might be a fanatical stamp collector for no other reason except the satisfaction it brings you. If one day a friend comes along and starts mocking you for the amount of time and money your spending on what amounts to sticky bits of paper, does that make stamp collecting wrong?
Preparing for a disaster might not increase your chances of survival at all, but its no more of a waste of time than stamp collecting.
As for my reasons for "being prepared"? As I mentioned in
a previous post its brought a good deal of order to my way of living. I'm forever learning learning new skills and aquiring knowledge. (everything from building shelters to learning how fast I 'm going to hit the ground whilst trapped in a falling elevator!). Above all though its peace of mind, a kind of alternative investment plan which I hope will never get used.
Lastly it's fun. Trying to light a fire in a force 10 gale with rain lashing against your face, I find comical and slightly ridiculous, but I still enjoy trying. If at the end of the day, our survival skills are never used, we'll all have good stories to tell our grand children.