Sony received far worse publicity than they received positively for this particular movie, which wasn't designed to create revenue and isn't even credited as a great movie -- there's been a lot of embarrassment over data that was released, and Sony will be a laughingstock for months if not years after this. Considering what a control freak Sony is as a company, and the loss of "face," this is not a path they would pursue.
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Aside from the understanding that perhaps the FBI did not release all the "evidence" they have regarding North Korea's culpability here, this seems a fairly reasonable assessment from what information is pubicly available.
No, North Korea Didn’t Hack Sony - The Daily Beast
If this is the case, Sony comes off as even more stupid, dancing like brainless puppets at the end of the trollers' strings.