This seems silly. I am photographer, and yes I feel photography is legitimately art. That being said, it isn't a "bias" to reduce a photograph's value because of its reproducibility, it is a rational position.

If you actually look at a piece of original art it isn't even 2D, you can see the indentations, brush strokes, or speckles where granite has floated onto the page from above. That's literally one of a kind, a print cannot re-capture that. If they do 100x originals, each of those 100x is subtly different and unique.

Unless you're doing "experimental photography" using raw photo sensitive paper, most photographs are reproducible, and each of the reproductions is identical. You can do things like limit them to 100x copies and destroy the negatives, but the depressing truth is all of those 100x copies are identical to one another and worse still if someone got hold of one of those copies they could reproduce them 1:1 with high end enough equipment (even hundreds of years later).

Something unique is ALWAYS going to be worth more than something which is not. Photographs by their very nature are born trivially reproducible, so their nature is to play second fiddle to other art forms which can be unique.

This may all change if they invented Star Trek style replicators tomorrow which can clone a famous artist's painting down to the atom level.