Although I didn't find any official canon reference to the subject, to my understanding, the S series isn't considered to be a simple point and shoot series at all, but they are designated to a different market segment and is marketed as SLR-like cameras, to the prosumer that looks for some more zoom, and some more manual functionality, opposite to the A series which are basically pocket point and shoot cameras.
Of course you'll find new A models with x6 zoom and some extra features, but these are the top models of the series, which don't represent the general guidelines of the series - up to x3 zoom, and automatic preset functionality.
