Why do mutinies happen?

Mutinies are relatively simple to explain. Bear with me as i do so... Onboard a ship, the commanding officer (always called "Captain" regardless of actual rank) has the sole responsibility for the ship and its crew. When a ship is sailing the high seas, especially in the old sailing days before the advent of communication at sea, the Captain runs the whole show. Sometimes the Captain can make harsh or unpopular decisions, but being the Captain, he cannot be overruled. Mutinies were much more prevalent during the early sailing age when the Captain owed much of his success to the crew and the crew knew this. He would often try to be as popular a Captain as possible to keep his crew happy. In the event that the Captain was very upopular, or through some agenda of one of the other senior officers, the crew would mutiny and either kill or imprison the captain. Unfortunately, this could end up in a death sentence for the crew because mutinies were forbidden and if that ship ever returned to home port, the crew could be summarily executed. Thus, when mutinies occurred, the ship and crew usually sought to harbor elsewhere or becaome pirates. I hope this answers the question effectively.