Earlier quoted context omitted.
You think the CIA did it instead? Other than it maybe being technically possible, what evidence or motivation would they have for doing that?
Before I answer, I'd like to state that I am an American citizen living abroad and I have no particular allignment to or against any country :) I don't know if the CIA did or would want to do this specific attack. But, I could grasp at straws to fit the Sony attack in line with the narrative of what I would call "1950s American Imperialism". In my view, the Americans took covert or overt actions for many decades now…
But "They have nukes!" would be reasonable enough reason to invade. Why not work with that narrative as opposed to "They're hacking us!"?
Some might say the US has a moral obligation to pursue regime change in N Korea, but US foreign policy has focused on isolating as opposed to invasion