I phrased it bad.
I was looking specifically at DK's matchups not Marth's. I looked at every character above him and tried to find a matchup DK won 6:4 or so. He obviously didn't have any with the top tiers, so I went down the list. Marth, Kirby, IC's, etc. He clearly doesn't beat any of them 6:4. I was just trying to show people that yes, DK may be underrated, but looking at his matchups his placement makes a lot of sense.
My point was that it's hard to justify the rise of a character, in a spot like DK, when he doesn't even have a single 6:4 matchup in his favor against characters above him. I should have been more concise with my wording.