Many people feel that Satan is firmly in control of what is going on the world right now. They feel that the world progressivly worse state.
Without pointing out the recent progress in medicine, human welfare, famine, poverty, and basic wellbeings (okay, so I did point them out), I think this view is somewhat questionable.
As for WHY that would happen. Well, its a hard question for me to answer, since I dont believe the reasoning behind it, but I will give it a go.
Satan is given a certain amount of influence in the world. Humans are then tempted. Humans have enough willpower to make the right choice, but often times do not. As with any habit, the more bad choices you make, the easier it is to make further bad choices.
Anyway, im not saying I agree that this is what happened, simply that it is some of the logic behind it.