I agree, it is a shame. Though people give Yooka-Laylee a lot of slack--and some of it is warranted. However, I consider it a worthy "third" installment as a spiritual successor, much more so than Nuts & Bolts despite the limitations of being an indie developed game (and to be honest, despite its heresy, had more fun with it than Odyssey). It is a shame, though, as Tooie was such a good game it would have been interesting to see how they took that formula further.
The moves are so perfect for Smash--in the 64 era, Smash was essentially a fighter of platforming characters, and nothing embodied that more than Banjo-Kazooie, with the exception of Mario. All the moves you learned as you progressed through the world, the freedom of movement, while still having that wacky charm. It's why I'm flustered when people suggest Minecraft Steve over them--have they ever PLAYED Banjo-Kazooie? The moves speak for themselves, and regardless of what some people may think, I'm certain Sakurai considers the intricacies of each new fighter's move-sets more than "well they're more famous and relevant."
It's why I feel like had the Rare situation not happen, Banjo & Kazooie would have certainly been in Melee and would now be perennial veterans. As Sakurai is using this game to bring back so many things that were once scrapped (e.g., Ditto) or considered impossible (e.g., everyone is here, Ridley), I feel like while there are more "relevant" newcomers, Banjo's importance cannot be overstated, and I consider the single-most important missing piece of the puzzle.
(I had an image I whipped up that portrays that feeling, but I've still yet to figure out how to upload images)