Because they believe the lie about it and spread it fear sells:-)
Because (somewhat ironically to me) the idea of the world 'ending' gives people purpose. A mission. Something to prepare for and to get everyone they know involved. Structure to chaos. That sort of thing.<br />
Of course, it's bogus. It's so obviously fabricated.
Maybe its their world..
Your profile says you're a teacher. Please say you're an algebra teacher.
"Don't nobody know not even the angels" = "Not even the angels know."
And it's about long count calendars, incorrect Mayan prophecies, astrological data, etc. All to be disproved, one by one. You should google it. It will make more sense. It's about as funny as the Y2K panic.
Only God knows when the true end will be but I will say this...the world won't end but something will happen.
Don't worry there's still a few shopping day's left!