I don't think it's unfounded at all. I think it's very much based in reality. While I believe it will be a lot 'BETTER' than what the Naysayers are expecting, it still will have some major hiccups. Starting with the 360 and it's game library towards the end of the generation and it's future potential game selection, Combined with negative rumors of things that sound mostly negative and it's primary competition actually doing and saying the right things (Sony)?
Only the biggest brightest of the Xbox fanboy crowd could try to act like that's no cause for concern. I fully expect it to be a worse system comparatively than the Xbox 360, with less games and less merit as a legitimate console. It's already taken all of the major Third party PS franchises, so the only battle it can realistically win is with fresh new games (Which with the lack of developers, I have always had my doubts on the quantity) and price.