It is a great fun to read Machiavelli because he is not beating around the bush. Nor is he trying to cover the dark side of human nature, since politics is just an extension of human nature. Machiavelli is telling the truth, or he is telling the part of the truth which has not been exposed enough. People are shocked to read "the Prince" because we are surrounded by too much "high morality" and rosy talks. We rush to defend our vanity and refuse to recognize or openly discuss what is really going on.
Machiavelli did not write "The Prince" to win the Nobel Peace Prize. He wrote the book to impress "the magnificent Lorenzo" in order to get promoted into crucial positions. Machiavelli's hard personal experiences and unsuccessful political life also explains why he holds so much negative views. At the same time, I found that Machiavelli is not as biased as the word "Machiavellian" usually suggests. Most of the time, I found him pretty fair and neutral.