A few years ago, an acquaintance had informed me that in an early draft of "Space Seed" there was a scene in which Khan had expressed disapproval toward Spock's existence. Purportedly, Khan had abhorred the fact that Spock is half human and half Vulcan and hence "impure". According to my acquaintance, Khan openly expressed his displeasure of the fact that, while humans have developed great technologies that have opened up the galaxy for them, they have interbred with other species instead of maintaining pure bloodlines.
Some of these views may have been espoused in the dinner scene where Khan and Spock argue over the Eugenics Wars:
At the time that we spoke of this, my acquaintance did not have a copy of this draft or access to any source confirming its existence. I did already know that, in at least one early draft, Khan was supposed to be a Nordic general named "Ragnar Thorwald". However, I have not come across anything indicating Khan's specific disapproval toward Spock.
Is it true that Khan openly disapproved of Spock's dual ancestry in at least one draft of "Space Seed"? If so, why exactly was it removed prior to the final script?
Curiously, in the actual episode, Khan does not even ask about Spock's appearance or question whether he is human or an alien, and the term "Vulcan" is never uttered in the episode even though Khan has never encountered an alien before (see transcript). Khan might have read about Vulcans and other aliens in the various reading materials he absorbed while in Sickbay. However, it seems unnatural that the fact that Spock is not human fails to come up when he and Khan first meet at the dinner. While such discussion could have occurred off-screen, it does seem that something has been excised from the script.