I know blood and guts do not make a game, but Nintendo HAS had a history of being squeamish with regards to that. You can't blame people for distrusting Nintendo now, especially since they're still pressuring their third-party developers to tone down violence. Blood and guts don't make a game, but taking it out can certainly make that game not what it's supposed to be. SNES Wolf3D, animal rights nuts badgered Nintendo into forcing Midway [or whoever ported it] into changing the wolves into giant mutated rats. Nintendo could have said "no, we won't force anyone to change it just because it offends people or makes children cry", instead they obliged.
And when Grand Theft Auto 2 hit the market in 1999 (peaking the popularity of the series at that time), DMA as well as their fans wanted to see an N64 port. Badly. But Nintendo wanted ten thousand things taken out or censored before they would authorize a manufacturing license, else no deal.
Was that necessary? WHY couldn't Nintendo just have said, "ok we're cool with that. here are the development tools you paid for, now make whatever you wish and let us know when you're done and we'll approve it"?
This is why: because they HAVE been aiming to maintain an image/reputation of family-friendliness... and making Banjo/Conkers simply as response to criticism is kind of chicanerous and two-faced, since AFTER they made those games they continued to have other games heavily edited for less gore/blood/entertainment/etc.
Let me remind you I have nothing against E-T rated games. And I have nothing against Nintendo (the majority of games I own total are from the NES/SNES era--hundreds of NES cartridges especially). I'm just against the shit Nintendo's done in the past to third-party companies (as recently as Doom for GBA), but as I understand these practices won't be going on for much longer if Yamauchi--who's been the nucleus of Nintendo's policy-making for as long as fossils have existed--retires soon and is replaced by someone who understands that Pokemon and mature games CAN co-exist in Nintendo's collective arsenal, without the need to coerce censorship.