If Laylee's nose was smaller, or if Yooka wore clothes, there would be no reason to poke fun at the main characters, and no chance for some self-deprecating humour, which is what Rare and Playtonic are very good at, as shown in Banjo and Conker, and in many of Playtonic's tweets and news updates.
The character design is weird, and that will make for some good humour in the end, which is what Rare was very good at in their games.
If Yooka wore clothes or Laylee had a smaller nose, there will be missed opportunities to make fun of their appearances and personalities, which is what the Banjo games and Conker also did, and that helped the tone, style and personality in those games.
I might add that Playtonic is fully aware how we feel about Yooka's nudeness and Laylee's big nose, and believe me, they're going to take advantage of that reception for some good comedy.
The designs are fine.
