I think it's the second-order stuff here. Even assuming Musk were to do a fantastic job at just clearing out inefficiency in a smart way (which seems unlikely given the actions he's taken/leaks around cutting funding based on key-word matching etc.), the higher-order point that someone can just buy their way into the President's inner-circle and have complete free-reign to seize government operations and make changes with 0 transparency/accountability seems like it does just stupid amounts of harm to the integrity of the system