Um, no. Each Super Mario Bros platformer presented one of the deepest, most extensive gaming challenges seen up until that time. Nintendo games were generally groundbreaking and challenging.
That's great game design. Like Sonic Team games. Fun to play casually but hard to master. They're not strictly for the casual because they did have their challenges for the hardcore but the games' priority was primarily to be a fun experience for casuals.
It's only in recent years that "serious video game" and "has blood and possibly swearing" have been seen as equivalent terms.
Some people do take that too far. I would object more to many people these days only counting high end visuals as hardcore, one of the most hardcore games I've seen come out in the past few years actually came out on the DS(Etrian Odyssey which didn't have impressive visuals even by DS standards). A game being cutesy is meant to appeal to everyone. Having safe for everyone content is the definition of casual.
Furthermore, their hardware was always at or near the top of the game when it was released. The NES, SNES, and N64 all had extremely competitive home console technology.
Ah yes, on B3D nothing can be hardcore if the hardware isn't impressive. The NES and SNES selling hugely ensured lots of 3rd party support but the same can't be said about the N64 which played second fiddle to the Playstation. That's where Nintendo's casual gaming orientation shined brightly as there weren't many 3rd party games to round out the variety of gaming genres on the console.
Comparing Wii Play to Super Mario Bros 3 or the overclocked Gamecube in 2006 to the N64 ten years earlier is frankly ridiculous.
No, compare Mario Galaxy to SMB3. Nintendo has had a problem with being too casual and not enough 3rd party support since the N64 days. Even Joystiq
mentioned that today.
By the way, Nintendo did not make or publish Conker. That was 100% Rare.
No, Nintendo was involved in that at least for a while I remember reading about it. Nintendo had a very close relationship with Rare in those days. I don't know why Rare ended up publishing it. On Wiki all I can find about it is 'Conker's Bad Fur Day is a Nintendo 64 video game developed and published by Rare, and distributed by Nintendo.' I'm not sure what that means since Nintendo didn't publish. Also look at the news reports for the game
here, it's always Nintendo presenting the game to the media and holding events for the game, like a publisher would. They appear to have distanced themselves from the project for release though, my guess is they had second thoughts and saw it as a train wreck.