This argument has been going on ever since photography was invented.
In my view it depends how you approach it. Art is creative. I have no doubt that the photos of Ansell Adams are both creative and are art. Is your photography creative?
Many people just capture scenes. I agree that simple scene capturing is not art. (Although it may occasionally result in an image that can be taken as art).
Others copy the style of their favourite photography "great" (like HCB for example). Thats OK when you are learning but at best its poor art as its thoroughly derivative.
You have to progress beyond that stage to be a real artist. You have to be,well, creative. Once you do this then you are on the road to creating something worthy of the appellation "art".
If you look at the work of HCB (sticking to him as an example) and study it, you will find that the thing that strikes you most is the
relationship between the elements in the photo, not just the elements themselves view individually. His genius was in picking the moment to go "click" His famous decisive moment. He composed in camera and "on the fly". You need an "artist's eye" to be able to do this well and result in an image that has the required "balance" between the elements - an image that works.That is not just capturing any old image that comes along.
It takes both skill (to be able to manipulate the equipment with the speed needed) as well as vision to be able to imagine the shot before it is taken and as the scene unfolds. This ability to compose "on the fly" is every bit an artistic skill as much as that exhibited by a great painter who does the same thing when composing his image on canvas - only the painter does it infinitely more slowly and has the ability to rework the painted image if its not to his liking. The artist photographer seldom has that luxury.
Art is also decorative. Look at the photos of Saul Leiter and tell me they are not decorative.
http://www.youtube.com/watch?v=B3wSjuImGu0
They are really quite beautiful. But art goes beyond being decorative. In my view it needs to make you
think and to feel an
emotion (other of course, that "god that photo is so bad I want to puke.")
For a photo to be true art you have to be able to look at it and wonder. It has to evoke something deep inside you. And the great photos do this. So yes, photography can be an art - but it all comes down to the photographer in terms of both their skill and what they are trying to achieve.