Both Shays's Rebellion and the Whiskey Rebellion happened after the US became independent. Therefore, I have edited your question to reflect what I think the correct question must be.
Shays's Rebellion and especially the Whiskey Rebellion were centered around issues that had come up in the time before the Revolution. Shays's Rebellion was about people wanting the government to be responsive to their needs. The revolution was partially about that. The Whiskey Rebellion, like the American Revolution, had to do with taxes imposed by a central government on people in a state (or colony). The American colonists did not want to be taxed by the central government in England. The rebels in the Whiskey Rebellion did not want to be taxed by the central government which was then centered in Philadelphia.
In these ways, Shays's Rebellion and the Whiskey Rebellion occurred because some Americans felt that the governments after independence were doing things similar to what the British had done to make the colonists angry before the American Revolution.