Cinema Geekly wrote:
The real argument is why did they go with the Henri Ducard fake identity gimmick? Clearly that is why they never reveled the real villains name in trailers and such even though it was a badly kept secret.
Maybe the months and months of free hype generated in the fan community in all those debates we had about who we thought/hoped/dreaded Harrison really was? (I mean... there are threads in this very fora, from barely a week prior to release, presenting arguments that Harrison was Gary 7, Gary Mitchell, a genetically engineered tribble, Arne Darvin, etc.) Seriously... months and months of utterly free promotion doesn't warrant asking "why", but "why not".
But with nuKhan, it's just one mystery for the sake of mystery. It doesn't even have a purpose in the film...
WTF?!? I'm pretty sure that Starfleet giving Khan a false identity probably had something to do with not wanting to advertise the fact that they had found, freed, and were working with a notorious historical war criminal. That seems a more than ample in-universe reason to me.