While I understand your cynicism, my experience in Shanghai and Beijing suggests that Google Maps are some way off between satellite and streetmap modes. I have not found the same problem (or at least to anywhere near the same level) in the UK, Chicago, Michigan, Korea, Japan, Germany, Slovakia and many other countries. There does seem to be an offset applied.
I suspect that Tokyo might well have more. Anyway, the loss of accuracy in such a case wouldn't cause a consistent effect like this - it's normally not in a consistent direction and generally doesn't put you off by so far.
An example in Shanghai: http://g.co/maps/m34n8 An example in Seoul: http://g.co/maps/4gk3t
Note the near perfect alignment in the latter, and way-off alignment in the former.