“The enemy broke into our nuke silo, killed our Air Force manned crew, stole the nuke codes, launched the missile. Not a big deal because we shot it down before it hit its target.”
Most of the time, actual harm is the most important issue. In this case because that office holds so much centralized power and authority over many aspects of American life (domestic law enforcement, some foreign law enforcement, domestic counterterrorism / counterintelligence / counterespionage, and security clearance background checks for all VIPs), the means are equally as important as the ends.
And I would throw in a wrinkle: what evidence is there that the dumps were not stripped of the most useful blackmail material? If I were in charge of a hack operation, I would dump the low impact stuff to show the world how much of a joke this guy’s security is, but only after I already used the best stuff to blackmail him months ago.