Even the motive for a lone wolf hacker with a huge botnet would make sense if they were impressing themselves with how good the hack was. If they could "trick"

Even the motive for a lone wolf hacker with a huge botnet would make sense if they were impressing themselves with how good the hack was. If they could "trick" the US into thinking it was North Korea, the lulz from that alone would be enough to have the whole charade to take on a life of its own. That's just a good a reason as any other motive for any other suspect given that I've seen.