Because many people, despite their intelligence, "intelligence" (something entirely different from true intelligence), logical thinking, and common sense, make many decisions based on emotions, (ex. choosing to let their mother die because they can't stand to see her like this, killing people because they hurt your friends, MILEY CYRUS, abortions for the most part, to name a controversial few) instead of logical thinking. Also, MONEY, POWER, and that little three letter word I dare not say on a website visited by children (but you know what I mean)
And sorry for double post, but I thought of another one kind of like the decisions based on emotions instead of logic and thinking: People seek immediate desires (that three letter word some of us are well acquainted to, but maybe not on a gaming website XD, eating lots of junk food, drinking, smoking, drugs, etc.) instead of considering what is important in the long run.
