Potential explanations:
1.It is a lot more fun to prepare for zombie apocalypse than to confront the inevitable decline into senility culminating in cardiac or respiratory death.

2.We have fabulously safe streets and fabulously safe water but spend billions on bottled water and firearms: victims of marketing.

3. The sample you have selected follow the ETS website: the rest of the world is better adjusted.

4. All doomsayers are wrong except for the last one.

5. Pessimists are always pleasantly surprised; optimists are always unpleasantly surprised.

6. A forum of people discussing the assertion that everything will work out for the best, no worries, would be very tedious.