Then it's probably because you're a gigantic, short-sighted, delusional fool.  Nothing has changed in thousands of years.  It's just a bunch of monkey tribes trying to invade, rape, and pillage everything from other tribes like the Mel Gibson movie Apocalypto.  Have fun being raped, murdered, and tortured by armies of infinite brown zombies, but it's not gonna be me.  They just noticed you have some shit they want so they've decided to come and take it.  Enjoy your demise.