I think Dixie's moment really should have been in Smash 4.
I mean, that game had a focus on adding characters from recent games, AND a tendency to add female newcomers. Tropical Freeze was recent, it was a masterpiece, and it brought back Dixie, who also was worked on a bit for Brawl. She had basically everything going for her, and yet... It's still baffling to me that she didn't get included.
Maybe the Japan side of Nintendo was really underestimating the popularity of Rare characters before the Ballot happened, while Retro Studios obviously had a better grasp on this side of the fandom.
And then the Ballot happened, and while Dixie was a pretty big request in her own right, K. Rool just had much more clamour around him, and of course Banjo & Kazooie are probably a bigger inclusion than either of them... so she got snubbed again.
It's really sad that Nintendo's best female character got treated so dirty. It's also a shame that she hasn't been used much lately, and that her role in Tropical Freeze was just as a power-up (apart from Hard Mode), so anybody who isn't accostumed to the original DKC trilogy sees her as just wig Diddy, while she's much more than that.
Though, if the ugly Bowser knock-off and the irrelevant cereal mascot bear managed to get in maybe wig Diddy can, too.
Closest thing to people wanting "boring" movesets are those who expect the Echo route. It's almost like they actively want to be disappointed, or something.
Eh, I think Echoes are fine for characters who wouldn't get in otherwise. It's that bit of extra fanservice. I sure appreciate being able to play as Dark Samus, even if she could have been more unique.
Dixie absolutely deserves better, though.