I'm honestly surprised at just how often this gets left out of the discussion when it comes to Banjo and Kazooie when it's their USP. People might bring up their "history with Nintendo", but that's severely underselling it. Loads of third parties have a history with Nintendo. The bear and bird were wholesale, unambiguously, Nintendo characters. Outright owned by them. Promoted in the late 90s as bonafide mascots alongside titans like Mario, Link, DK, Yoshi and Pikachu. They were Nintendo All-Stars before Smash even immortalised the concept. And we lost them. I feel like people who didn't grow up with the Nintendo 64 have zero reference point for just how much of a bummer that actually was. Like, imagine if Splatoon had been developed by a 2nd party company who broke away from Nintendo after Splatoon 2. People would be heartbroken, and rightfully so. I don't resent younger fans for not having any attachment to the characters if they were before their time, but I'll admit to getting a touch frustrated when people accuse the fan desire for them as just down to nostalgia. Plenty of other Nintendo characters and series have been on the receiving end of neglect or ill treatment, sure, but they've never been lost. Other third parties are, at the end of the day, just guest characters, hanging with a crowd that they don't fully belong with. And, hey, I'm not knocking that. That's, broadly, the appeal and the fun of third parties. But Banjo and Kazooie wouldn't be that. They'd be a reunion with a family they were severed from, and that's why people get so passionate about them.
I know I'm preaching to the choir here and this post is largely pointless, it just gets frustrating how perhaps the most important fact about Banjo and Kazooie and the weight and meaning behind their inclusion seems to get lost, for some reason, when he comes up in general character speculation. They're not just any old dated 90s platforming mascot.