What a huge (and incredibly interesting) topic.
Thanks for introducing it Frank. Might I ask why you did? Personal angst or just plain interest?
Firstly, as someone who has lectured in Art Philosophy, been an art critic, and is now a gallery director (as well as passionate photographer), I'd have to say "Yes", there is good and bad art.
In answer to your question, I would refer you to the Scottish Philosopher David Hume - but I don't want to bore the pants off of you, so I'll summarise as best I can (apologies to Hume).
His position (and mine too as it so happens), starts by looking at the old "beauty is in the eye of the beholder" argument. Sounds reasonable enough really, and we hear it all the time. You like what you like, and I like what I like, and if that just happens to be Velvet paintings of Elvis, then so be it. You can't tell me I don't like them, and you can't tell me not to like them, cause that would be elitist - and we don't want to be elitist now, do we?
Art (and photography) in this sense is SUBJECTIVE - it's simply what you like, and that's all there is to it.
BUT - is this really an appropriate argument? Is it really the case that all things are created equal, and there's simply no inherent value in anything?
Value judgments can (and should) be made about things all of the time. Not all red wines are created equally, Beethoven created better music than the Spice Girls, and the Mona Lisa is a better painting than a Velvet Elvis.
In any genre there are "accepted" classics, which can (and are) appreciated by a wide range of people and classes. To say that there is good and bad is NOT to be elitist - it is to acknowledge certain factors inherent in objects that make then 'special' and worthhy of importance.
There is a reason why Ansel Adams is world famous. He's not just some bloke who took a couple of kinda interesting pics. And there's a reason why Beethoven, Picasso, The Beatles, Tolstoy etc are also famous. That's not to say that everything they did is brilliant - but they certainly got it right more often than not.
Now of course the next (even bigger) question is "What is the "it" that they got right"? What makes a great work of art?
If I knew that, my friend, I'd be very very rich.
Sadly, I'm not.