Why does Katniss want to start and uprising?

By daring the Gamemakers to declare her and Peeta dual victors or watch them both die, Katniss unwittingly becomes the face of rebellion in Panem. Even though she was not thinking about the consequences of her actions during the Games, Katniss's behavior is a clear threat to the authority of a country that depends on the cooperation of its Districts. Katniss challenges the President, saying that if the Capitol could be brought down by one girl, then it is not as strong as he thinks. This conversation reveals both the state of Panem and the motivations and feelings of each character. Snow is ruthless and calculating, willing to hurt the beloved victor of the Hunger Games in order to remain in power. But Katniss also strikes a nerve - Panem is in a more precarious situation than Snow likes to admit. Katniss is defiant and detests the man and his corruption but she ultimately chooses to do her best to protect her family. She will keep up appearances to quell the uprising, but she cannot deny that rebellion is boiling up under her stoic exterior.  

She wants to kill Snow. And she does in Mockingjay Part 1 and 2. Watch the movie if you don't believe a SINGLE word I say.

Right. But then it was District 8 who did the uprising... right?