Why are NATO, the European Union, The U.S. and everybody else making such a big deal about Libya?

They talk as if so many people have died when barely anybody did. 1 million people died in The Rwanda Genocide 17 years ago, 5.4 million died in The Democratic Republic of the Congo just 7 years ago, 100,000 in Sierra Leone etc any nobody did a damn thing. but now there talking about Gadhafi killing civilians when he's fighting an armed rebellion against his rule, and the rebels kill, and torture just as many pro-gadhafi civilians. Why is everybody sympathizing, and siding with the rebels? Also, if the Arab League cares so much, how come they aren't enforcing the no-fly zone or incorporating a more direct approach to the regime? Why is it always America who cleans up the world's mess and then is chastised for doing so?