Because the corrupted and evil are willing to sacrifice anything and anyone and covet over their time in this mortal coil. The choice of free will was given. It will only stop when the righteous make another choice of free will and aren't afraid to sacrifice their time here to stop them. At that point who do you think the advantage will go too? Those who will avoid any risk against those who risk everything. Once you see it you will understand it can only go one way.