Which Video Game Console Has Better Quality Graphics- Microsoft Xbox (not Xbox 360) Or Nintendo Wii?

Microsoft’s original Xbox console has ‘good enough’ (actually ‘great’) quality graphics (that are noticeably better than those on Sony PlayStation 2), and looking at hardware specifications of Microsoft Xbox and Nintendo Wii, one can conclude that both are nearly equivalent to each other. Why does then everyone keep whining about the graphics quality of Nintendo Wii (in comparison to Xbox 360 and PlayStation 3), when Wii already has ‘good enough’ (in fact ‘great’) quality graphics?
Have people suddenly started finding the graphics quality of their (original) Xbox systems poor, just because Xbox 360 and PlayStation 3 have far superior graphics?
Think of it this way- will people suddenly start finding video quality on their DVDs as poor, now that HD DVD and Blu-ray formats are available?