I'm not going to directly comment on nintendo's advertising because I don't really pay attention to videogame advertising. I'm not criticizing you because I don't know their exact situation and you could very well be right.
Advertising is more complicated than a lot of people on VGCHARTZ think. For instance with certain JRPG's or niche games people think they should advertise more. But lets say you spend 30 million extra on advertising. You'd Have to sell ~500,000 copies at full price to break even. Which isn't what you want to do, you'd want to expect that 30 million investment into 60 million revenue or so to justify the extra risk. (These aren't exact numbers, but when investing there's more things to consider than # of copies sold, such as cost/benefit, IRR, etc).
Some things are advertised to high hell, and don't sell, some sell with viral, word of mouth, twitter marketing (essentially free), some products are niche, and are going to sell to a niche audience, and advertising isn't necessarily going to increase that niche by that much. There's different strategies and a lot of effort is generally put into them.
That said, nintendo's current strategy with Wii-U isn't working, and the Wii was not a niche device before. So what you say could very well be exactly their problem. I don't know much what there strategy is, or if they've changed it.
