Probably because "I am the Wind" was just as much the butt of jokes and received just as much criticism as the intro's voice acting. Which is a shame because as cheesy as the song is, there's nothing technically wrong with it. Cynthia Harrell is a great singer (same lady who did the main theme of Metal Gear Solid 3 [which is also pretty cheesy as far as the lyrics and all go]), and there's nothing wrong with the work of the musicians either, assuming you don't have some bias against jazz, which I guess is the main problem people have with it since they feel it's out of place (but, really, it's not like all of Yamane's tracks are in a single musical style either). Personally, I think it's nice when a credits theme does something unique, different from all the other music in the game.