This is so wrong, on so many levels, that I don't even know where to start.

There are plenty of potential photographs that even modern sensor (or film) technology just can't do, like with questions of dynamic range. There are opportunities for cleaning up noise and sharpening to create a technically-better image. There are reasons beyond count for compositing of different kinds.

But most importantly, supporting the artist's efforts to achieve their vision is the whole point. If someone vision can't be achieved either with their physical toolset, or with their suite of tools, why should they limit themselves?