I'll go further though. When MS brought Rare, they got all Rare IP (Killer Instinct, Perfect Dark, etc.) but no Nintendo IP except for Banjo and Conker, who were technically DK characters. MS got the rights to those by paying extra and I think Nintendo made the correct move to sell both of them. They didn't lack for platforming characters and didn't have any teams lined up and interested in making games for them (especially Conker but also Banjo- the humor in those games wasn't Japanese humor and none of them got the playful nature of Kazooie's constant insults) so in this case they sold the two off at what was definitely going to be the height of their popularity/value and invested the money into something, anything, else.