And why exactly should Batista win this?
Just pointing out that the label of "incredibly overrated, roided up guy" is just as (if not more) applicable to 'Taker as it is to Batista. But to answer your question, because Batista is not only stronger and every bit as aggressive as 'Taker, he's also got the better record in gimmick matches, which I'll get to in more detail in a moment.
I couldn't give a fuck less about his overall gimmick match performances. He is 3-2 against Batista in one on one matches and he's 2-1 against him in those that were gimmick matches.
And if we ignore the matches with an unclean or otherwise controversial finish, the score's even. Which of course means we'll have to look at their past results, which show that 'Taker bleeds to midgets and midcarders without returning the favour. Batista is able to hit harder than either of those types of wrestler while being far harder to hurt.
Taking that into account Batista is the rightful winner of this match. End of story.