DK getting some great results, you love to see it. Astonished that Funky got higher placement than Dixie, but happy all the same.
WOW, Smash fans REALLY love Donkey Kong Country.
What can I say? The Kongs are appealing characters.
I think a noteworthy thing to bring up is that DK is the closest series Nintendo has to a traditional comedy, other than maybe Luigi's Mansion or Punch-Out. Warioware exists but that's more focused on the offbeat Japanese "brand" of comedy, as opposed to DK's more slapstick approach.
Point is, people like seeing funny characters, which is a niche that Smash could always use more of. The fact that all of the characters are well-regarded and can easily stand on their own also helps.