Time Turner said:
It's exciting to visit a new world and see new characters. New characters means new possibilities for stories and interactions with other characters. The difference between Bombette and Bobbery is huge, and I am incredibly glad that we got Bobbery's storyline instead of just seeing Bombette again. Beyond that, even if they aren't new species or whatever, if the large majority of the cast is just taken from the last game, then why not just play the last game?
Well yeah, new characters do bring something to the table, and I did enjoy Bobbery.
My complaint with what they were (and to a lesser extent, still) doing is that they just bring in dozens of new characters and just throw them away after one game.
At the very least, they could bring back Goomba King again.