Why do preppers prep?

Preppers are preparing to minimize the challenges that life throws at them. They do this by carefully evaluating their risks and understanding their vulnerabilities. Then preppers take steps to mitigate the possible damage those risks may cause.

Are doomsday preppers paranoid?

Yes, some preppers are individualistic to the point of being antisocial. Rightwing survivalists, in particular, are often motivated by paranoid, apocalyptic, and racist or conspiratorial beliefs. A massive doomsday industry caters to their fantasies with expensive survival supplies of questionable utility.