I think that photography is first of all a craft. The craft in this case "photography" is one possible means to produce a work of art...but not necessarily the only one or not necessarily always successfully. Simply because it is "photography" does not automatically elevate it to a position of "art".
I think that for a photograph to be seriously considered a work of art it must elicit an emotional response within the artist and others as well. That response transcends the degree of competence the photographer may or may not have.
I have seen some very beautiful and technically perfect photographs that bring nothing in an emotional content. They may be "pretty"...but I am rapidly approaching the point of ad nauseum with "pretty" photographs.
"That's just it, nobody does if you think about it. If you say "painting is an art" chances are most people will agree with you. Of course some might start to get too technical, dissect your sentence etc, but overall I think most will agree with you."
I must inform you that I do not agree with the "painting is art" generalization. To me painting, again, is a craft that may be used to produce a work of art. But not necessarily so.