Why Was Gaddafi Overthrown?

I will emphatically state that I was never a fan of Muammar Qaddafi or any authoritarian leader, but I was deeply troubled by the American led overthrow of his regime. It is obvious that the rebels were armed and government sites were bombed by NATO troops, not because of the violence it used in suppressing a revolt. By African and Middle-Eastern standards, the Qaddafi regime was not particularly brutal or corrupt and actually had some impressive accomplishments: 

From 1977 onward, per capita income in the country rose to more than US $11,000, the fifth-highest in Africa,^[56] while the Human Development Index became the highest in Africa and greater than that of Saudi Arabia.^[57] This was achieved without borrowing any foreign loans, keeping Libya debt-free.

The presence of oil, combined with his unwillingness to follow the lead of the United States and the European Powers is the most probable reason we engineered his removal. And in the end, what did we accomplish? There is nothing that indicates that the fragmented regime of the rebels is any more democratic and popular than Qaddafi's. So far they've harassed and even massacred black Libyans and by overturning the previous ban on polygamy, they've shown an inclination towards Islamic Law. And there is no reason to believe that their enthusiasm for the western powers  is anything more than a transitory phenomena. If the new regime doesn't deliver on its political and economic promises, soon we will get blamed for its failings. All this for the bargain of only $1 billion, paid for by you, the American Tax Payer!