Simon Pegg, Zoe Saldana, John Cho, and Anton Yelchin bear/bore hardly any resemblance to the original actors except in ethnicity. Ben Cross looks very little like Mark Lenard and doesn't even have the same accent (though he's a better match than James Frain). These are characters who had been seen in a number of prior movies and were pretty "iconic" in their own rights.
I can agree that Cumberbatch was not the best choice for Khan. But that doesn't mean that there's anything rare or intrinsically wrong about recasting a role with an actor who bears little physical resemblance to their predecessor. Nobody would ever mistake Roger Moore for Sean Connery. Or Dick Sargent for Dick York. Or Val Kilmer for Michael Keaton. Or John Carradine for Bela Lugosi. Actors aren't models. They aren't cast on looks alone.
I guess part of it comes down to the fact that I disagreed with redoing Khan in the first place--when you get down to my most basic objection it is that. It lacked originality to me. They took a villain that was very well acted by Ricardo Montalban from a movie that was one of the best of the series and basically tried to go to the well again. It was also the 3rd movie in a row to go the old villain has a grudge route. I was relieved initially when his name was revealed as John Harrison. There were all kinds of rumors that it was going to be Khan and when it started and wasn't I was like thank God. Then when he revealed his real name was in fact Khan, it was a face palm moment for me.
All my other arguments are just symptoms, secondary to my primary objection and that is I didn't want it to be Khan at all.
But I do love a good debate. And I will say you are an excellent debater who takes nothing for granted.