If I went into this entirely cold, knowing nothing at all about Khan, this movie would've failed to sell me on why I shouldn't sympathize with him.
First we've got the explosion set off by a Star Fleet officer, but no, he was coerced. OK, but then later we discover the same thing's true of Khan, and while Daddy Redshirt killed 42 of his co-workers to save one little girl, Khan's going after the people who have captured him, experimented on him, forced him to make weapons for them, all while holding 72 people hostage. (Though I'd also buy it if Khan was coerced into coercing Daddy Redshirt. Hard to tell, the conspiracy here is kind of vague. Dreadnought-class ships are kind of big for skunkworks, especially since there's one listed in the original Starfleet Technical Manual...)
So he surrenders and gets hit *repeatedly* by his captor. One shot in anger I could understand, the rest was just "let's show just how hard he is to hurt". This is Star Trek. We're the good guys, we don't torture prisoners. And Spock just stands there? If my friend or CO was hitting a prisoner I'd've been trying to stop him as soon as I saw him pull back for the *first* punch. (Hell, "friend holding back angry best buddy" is a classic trope, almost a cliche when applied to the logic/emotion combo of Kirk & Spock - Abrams should be all over it.)
Then they're working together, and at the moment of triumph he gets shot in the back by an ally. So now it's his turn for the punching in anger - hmm, start with punching, then a knee to the gut - that's a familiar sequence. But tally up who punches who more - it's not Khan.
Then the big fistfight in the air over San Francisco: one pissed-off Vulcan who's lost a captain that he never seemed to be *that* much of a friend to, against a super-soldier who thinks he just got tricked into *blowing up those 72 hostages*.
(And why couldn't Old Spock's advice be "find a nice isolated planet for them, just make sure it's not Ceti Alpha V"?)