Let's face it, Nick Meyer and his crew loved Ricardo and his portrayal in "Space Seed", a highly regarded TOS episode, and simply brought him back to make an amazing film. That's what made the character iconic. It was what they did with him, at the time, with that actor. It was a unreasonable assumption to place so much import to Khan in the overall Trek universe beyond name recognition where the new team failed in the writing. It was lightning in a bottle and they couldn't recreate it and were left with fans going huh? and new fans going who cares?
Huh, wait - what? I haven't checked in on this thread in a long time and now I come back and Bry is speaking ill of the new movie?!?! I must have missed Rod Serling standing somewhere around here narrating my journey into the Twilight Zone.