nexuspunk, your logic about Mario Kart 8 is flawed. Ever since the first Mario Kart game, every Nintendo console only had one version of Mario Kart released for it, with the exception of the GBC having none. The 3DS got its Mario Kart game years ago with Mario Kart 7, which is still being played regularly today. 3DS didn't miss out on its share of Mario Kart, it was simply the Wii U's turn to get Mario Kart.
As for the marketing aspect of the two Nintendo consoles, the 3DS doesn't really need too much marketing as it pretty much sells itself due to the legacy of Nintendo's handhelds, especially the DS' success in the previous generation. As soon as Pokemon X/Y came out, there was little need for Nintendo to do anything else to sell more units. With the Hoenn remakes and Smash Bros on the horizon, word of mouth marketing will do as good of a job as any marketing campaign. By the end of 2014, the 3DS will be printing money all on its own like its predecessor.
Nintendo is making the right move to focus their efforts on the Wii U, as it has drastically underperformed to what was initially expected. The source of the Wii U's problems can be traced to Nintendo's own decisions, therefore it only makes sense that Nintendo would be the only ones that can do anything about it. One of the main reasons that the Wii U suffers in the 3rd party department is the lack of DirectX support. The Wii already made it hard for third-party developers to include Wii in their multi-platform releases with its lack of HD output and penchant to push the motion control gimmick. Having learned from the headaches of the past, the 3rd party developers started abandoning the Wii U when they learned it wouldn't support DirectX, something that both Xbox 360/One and PS3/4 support. The cost of development just became too high to be worth the risk. Therefore, like they did in the first video with the DS, Nintendo is putting forth a large-scale 1st party development in efforts of regaining the trust of the 3rd party developers. Sony needs to make sure they do the same thing with their next handheld console if they want it to survive.
Foxi, I wasn't trying to say that specs don't matter at all. There's always going to be a curve of minimal technological progress that must be made to remain competitive. I was merely trying to mirror the point of the video that having the best specs tends to hurt more than it helps. I agree that the NES wouldn't survive in today's tech environment. However, having an overpowered system is just as detrimental as an underpowered system.