Putting a twist on the argument

This goes back to Ed Book's comments about the in-camera manipulations that digital cameras do and about Photoshop manipulations. Below is an image that "all I did was resize it in Photoshop":

© 2002 Michael R. Barrick

This picture was created entirely in-camera using the "whiteboard" settting of the camera (which is intended to capture text written on a whiteboard). So, by the conventional logic of the photography groups this would be a "pure" photograph, unsullied by additional "cheating" in photoshop. Of course I could have gotten exactly the same effect by using Photoshop to reduce a photo to a 1-bit pixel depth. Or by creating an old-fashioned halftone using traditional photographic techniques. Or I could have drawn something quite like this with a pen and ink.

So what is more "pure" and why? And why does it matter at all?