Sony and Microsoft do care about gaming, however they look at it from a different perspective than Nintendo. They have invested a lot on their consoles, fight for exclusive games of game content, because of their interest. It's foolish to consider the opposite.
The real difference comes in their perspective towards gaming. Sony and Microsoft relied too much on technology to deliver a gaming experience and there are reasons to applaud them for that. However, the new consoles offer other nongaming related things making them more of a media hub for different services, and games is one of them. This does not mean that it's not relevant, on the contrary, gaming is their door to customers to offer them other services (Blue Ray Capabilities, media streaming, Netflix, online community, you name it). Their investment in gaming relies on raw power, leaving the games, the software, the experience, to developers.
Nintendo on the other hand is a gaming only company, videogames is their central core and all services and investments revolve around this. This is why the DS and Wii are so different from what we expect of a system, because the focus is gaming experiences only, to give them something new and fresh to as many people as possible. They cannot provide the non-gaming services Sony and Microsoft do on their respective consoles, and this is why they didn't go the HD route. They focus on games for everyone and they should be applauded for that.
