I will concede that the Wii is the only "true" console in that it's primary and ONLY focus is on games, but your points for backing it up fail.
Since my time, entry prices for consoles were between $199-$299 (at least the decent consoles, not the 3DO or Sega Saturn lol). The 360 was already there with the Arcade model. That kills the affordability point, unless the PS1, PS2, N64, Xbox, Dreamcast, etc were "unaffordable"
Accessibility: Whether by "pick up and play" you strictly mean the controller or by the games, Sony has been both. The PS controller hasn't changed in like 14 years and there are still no complaints. Don't fix what ain't broken. And with regard to games, is Halo inaccessible? CoD? Street Fighter? Burnout? The only game out right now that's an "extensive tutorial" is LBP...but the end result is infinite replayability as long as people have imaginations
Local multiplayer: Go to any sports games, fighting game, FPS, LBP (again lol), etc. and you'll find local multiplayer.....seems graphics weren't ditched for this. Where did you even come up with that?
And as far as differentiating....the Wii has Nintendo games, a few 3rd party gems, and then junk. The HD consoles may share some games with the PC (more so the 360) but they have their own exclusives (between each other, not including the PC, and then console specific exclusives too) and not to mention XBL and PSN games.
I don't see how inserting a hard drive and having firmware updates are making the consoles more and more obsolete (as some have put it). Those things make the consoles last longer.
