Why do some people love predicting the end of the world as we know it?

Perhaps it's because the scientists are correct. Ozone depletion was occurring, and now that action has been taken, the situation is improving. Concern about impact of a meteor is a valid concern, as it has happened in the past. Concern about water supplies is also valid because many areas of the world are running out of water. Perhaps you just don't want to be concerned about anything except what you will watch on TV tomorrow, and don't want to bother addressing the long term welfare of yourself, your children and grandchildren.