That's true; after all we did get Lucas and Roy in spite of them not appearing in a game outside Super Smash Bros. for nine and thirteen years respectively. DLC I feel is going to be an outlet for "characters without a future" to be added in as playable characters if Lucas and Roy are any indication. And while Ryu obviously doesn't fit this, his appearance in Super Smash Bros. is inspired mostly by Street Fighter II. And King K. Rool just happens to fit alongside Lucas and Roy as someone that may have been lower on consideration due to a lack of recent appearance. At any point, we could have gotten a LOT worse that couldn't be fixed by the Smash Ballot or a major DK appearance.
I would be so for this. The Kaptain K. Rool design is a must.
I honestly feel like the ballot is basically the best thing for K. Rool, outside of a new game, and even that is arguable.
-Popularity rules the ballot, and that's K. Rool's biggest selling point (literally).
-Dixie wasn't in the base game either so people don't think "there's enough Donkey Kong characters."
-Wolf's (and initially, Mewtwo's) removal and Ridley's deconfirmation has left people wanting more villains.
-No super heavyweights added to the game.
-His competition is mostly either veterans (with Lucas and Roy already added) or minor leaguers.
-No active role in the game.
As someone else said, it's gotten to the point where even non-fans will be very confused if K. Rool doesn't get in.