2005 was the end of the dark ages for Nintendo as a company, but most of the effects hadnt been felt yet. The Wii wouldnt come out until 2006 and its big titles were mostly unannounced, the DS was out but didnt really pick up steam until summer. You would expect the big boost to be in 2006, and indeed Nintendo kicked arse that year. But why a year earlier? Was it DS hype? E3 2004 (TP reveal, Reggie debut, etc.) hype? The start of Squares slow decline making Nintendo seem better?
I cant think of a single major shift that hasnt had a clear explanation except possibly that one.
Yeah, it's still a mystery to me, too, especially considering that Mario was seemingly the biggest beneficiary of it and we were still two years away from Galaxy. I'm sure TP and Wii hype helped, as well as the slow decline of Square. Sometimes they just looked better because their competition got worse.