That's more about Nintendo being concerned with retaining value in their products. It can't be used as an argument against cross buy.
Again Iwata specifically stated he wanted to move to an ecosystem as the business model going forward beginning with their next system. He pointed directly to iOS and Android as examples and mentioned that they do not have to worry about software droughts because software works across all devices that run on that ecosystem.
This isn't an argument about how cheap Nintendo is or isn't. This is a brand new business model for the company and Iwata has specifically stated his intention to move in that direction.
Besides, look at the sales of key games on Wii U. How much more software would Nintendo have moved if certain games were cross platform? How many more Wii U consoles would have been sold if key Nintendo 3DS games were playable on Wii U? Imagine buying a Wii U and being able to play games that you owned on 3DS on your home console? How many more new games would Nintendo have been able to make instead of making a Mario Kart specifically for 3DS and then for WiiU. Or New Super Mario Bros, or Animal Crossing (we know that's on the way), or any other game that is clearly playable across platforms?
My point is that the question we should be asking is not how cheap we think Nintendo is but how could they use this kind of ecosystem to their advantage? Why are they talking about it? If you try to break down the benefits, then you can begin to understand what Nintendo themselves might be thinking. Iwata wouldn't be interested if it was going to lose the company money.
My thinking as well. And they've stated they can release even more hardware. This opens them up to experimenting aggressively if they choose. Personally I hope they put out ever more powerful models of all their hardware lines every 2 years. Oh that would be glorious IF DONE RIGHT.