Wait a minute...
You have a problem with them using Khan who we haven't seen on screen in thirty years, but have no problems with Klingons and Romulans being in it? Those two have been used over and over and over again in the last forty-five years.
I really don't understand...
Khan - a specific character
Klingons - species / culture
Romulans - species / culture
both potential sources of countless diverse characters.
Nero and his gang were like no Rommies we've ever seen before. General Chang was very much unique too.