This is half true but I think half not.
A key part of the Indian independence movement, and the US civil rights movement, was throwing it into absolutely crystal clear relief what was the violent and unjust nature of the system they were up against. Gandhi's speech to the judge, black men marching in orderly rows in suits and getting attacked with dogs and water cannons played out on TV, the absolute inescapable moral logic which gradually worked itself bit by bit to penetrate into the public consciousness -- these were important parts of why both of those movements worked.
Certainly more than asking politely is required; I don't fully disagree with Shakur's statement. But oppressive systems are massive things, made up of people who have all kinds of motivations and levels of humanity and understandings of the world around them. Abandoning completely the idea of appealing to the moral sense of the people involved in them is a mistake, I think.