How much more effort should have been put into casting a Montalban look-alike? Cumberbatch has similar facial features, black hair, and white skin, and clean shaven. Are you suggesting he should have been given makeup to darken his skin as was done with Montalban in Space Seed, but, not in WoK?We should simply say that Khan is Sikh, but is not practicing, or that he is but is not particularly committed to his religion. Many Sikhs, especially those who are part of the Sikh diaspora in the West, don't obey the Kesh for a variety of reasons, and Khan could simply be one of those. To get hung up on his lack of facial hair or a turban is to be rather pedantic in defending the decision to cast Benedict Cumberbatch in the role, when they should have made at least some minimal effort to cast an actor who resembled Ricardo Montalban, considering that, as others have pointed out, the two Khans are the same person.
It is all a problem resulting from this whole parallel timeline nonsense. Though I was opposed to the idea of "rebooting" Star Trek in the first place, they should have simply gone for a full reboot instead of half-assing it the way they have. Abrams, Orci, and the rest can't say they were concerned about the fans taking issue with the idea of a full reboot as since they took over control of the franchise they've made perfectly their disdain for those fans who would care about such a thing.
And why, if the complaint is about being Indian or Sikh, would they possibly want Khan to have a thick Latin Accent?
Why is a light skinned Mexican Guy, born to Spanish parents, so much more believable as a Sikh or an Indian than a light skinned British Guy? The British have a long history with India, it is way, way more believable for a British guy to be an Indian then it is for a Mexican guy (especially with a thick Latin Accent). Mexico and Spain don't have anywhere near the relationship/history with India that Britain does.