I can maybe see DK rise about TL and Pit (even though I believe at the core those two are at least slightly better than him). I don't think DK is that bad, but looking at his matchup spread it doesn't suggest much. He has harder counters than TL or Pit (Dedede is definitely harder for him to beat than MK for TL/Pit. Even with the Infinite removed, Wario and Dedede still give him a good run for his money. Not to mention the solid 60:40 or potentially higher matchups against him like Falco, Diddy, and MK.) He also doesn't have many "strong" advantages over notable characters. MK beats him, Wario beats him, Falco does, Diddy, Dedede, characters like Olimar too can give him a good run for his money. DK doesn't do that strong against the top tiers. Even in the A tier, his better matchups are at the lower levels. IDK who he beats 6:4 in either top tier or A tier. Actually, even looking at the people ahead of him in B tier, I don't see a 6:4 matchup in his advantage. I don't think Marth loses to DK 6:4, nor Kirby, ROB, G&W, IC's, etc.
If he doesn't even have a 6:4 matchup in his favor against the characters above him, then he better pull some weight HARD if he wants any real shot at advancing up.
If he doesn't even have a 6:4 matchup in his favor against the characters above him, then he better pull some weight HARD if he wants any real shot at advancing up.