Nice OP Rol, however, I think you are pushing this conspiracy theory too hard. It really comes down to a smaller part of what you said in terms of long-term business decisions.
We all know the Wii was not considered to be anything but a failure before its launch. As such ALL 3rd parties put their money in PS360 and what that really means is they spent TENS of MILLIONS in developing software tools and APIs to create their games in efficient ways with the best possible results.
In 2007 when it was obvious Wii was an avalanche of success, the people who sit at the heads of the companies had a choice; spend another 'TENS of MILLIONS' to create a stand alone Wii engine that really took advantage of the system and could easily port games to PS360 (as happened to PS2) for future AAA games (which also reduces the expected return on the HD tools) or spend a far smaller amount of money (probably less than a million a year) on improving the tools they now have working from their first year games.
Throwing aside my fanboyish love for Nintendo, I too would have chosen the PS360 path.
It just makes sense, you know you'll make tons of money by keeping the HD path with the better concentration of core gamers. You know you can retool the PS2/GC engines from last gen for a far smaller amount of investment to capitalize on lower end Wii games over time. So why do it any other way? Where's the real financial gain? On top of that, those actually making the games have stressed an opinion to want to continue to push boundaries that you simply can't do on Wii. So its a win-win scenario to continue this HD path with a nominal investment on a Wii/PS2 path.
In hindsight we can see this clearly. No 3rd party AAA games, no 3rd parties pushing the limits of Wii's capabilities, no surge in core market as happened on DS, most games on Wii are also on PS2 as identicals (as long as they didn't require wiimote).
3DS demonstrates Nintendo's change though and the next home console will probably push that same envelope and come out with a far more comparable machine to whatever MS/Sony build. Nintendo has learned this lesson; they MUST remain within a technologically relative distance to their competitors or they will get ignored. 3DS shows this as its been mentioned to be far more capable than the PSP even with 3D effect in place.
