But that's the REASON it happens. Because if you have more than one console as a lot of people do, you can only buy it on that console.
I think you misunderstood. Nintendo has annually been the number one software publisher in terms of combined sales for years, independent of platform. That means they outsold Activision or EA in combined sales of all platforms. That's not the reason they outsell them, they would sell even more if they were multi-platform.
Also, 3DS only recently broke the 3 million sales barrier, if it sold 8 million there wouldn't be a problem.
A number of you are failing to understand that iOS is a serious competitor, it has full-length quality games. There are good virtual joypads for traditional games and obviously new games don't have to use traditional controls. The meh sales of the 3DS are partly due to price, but iOS is most certainly a huge factor.
Nintendo has been successful for years mostly because of their handheld dominance. Trust me on this, I've been a fan for years. When they lose handheld dominance, they're in trouble. Yes the Wii and DS have made them extremely successful these past few years. Yes Mario Kart Wii continues to impressively tear up the charts. But the Wii began to plummet significantly this year and is now consistently outsold by PS3 and 360. Last year it was predicted to have crossed 100 million by now and likely isn't going to get there. The DS is on it's last legs and the 3DS has an uncertain future.
Have you seen the successor to the Wii? It's a 360/PS3-level device with a resistive touchscreen controller that has a 480p resolution. I'm highly skeptical and I love Nintendo. As far as I can remember, nobody calls upon Nintendo to go software-only every 5 years, this was only brought up during the gamecube era until the DS and Wii 'saved' them.
As for the .99 business model, nobody has to follow it. It isn't a standard. It's standard for a lot of crapps and sales and a few underpriced gems. I have several games that cost $5-$10 and a couple that cost $15 (FF3, FFT) which still isn't bad. People pay more on lunch. I know people who are too cheap to pay .99 and complain that everything isn't free. When the app store has more quality stuff at a higher price, attitudes will change.