People have many different opinions on art.
Art in a conventional sense, paintings, sculptures, drawings, sketches and things like that can be art, but to a cook, a finely prepared meal would be art to him.
A carpenter could create a perfect piece of furniture, and that would be art as well.
You don't necessarily need to be a creator to appreciate your own view of art.
Art to me, is something that messes with your head, a good psychological horror movie, a game, anything that makes me thing hard. Dali's sketches affect me greatly, but so did Portal.
In summary, your opinion is your own. Any attempt by any party would have a hard time to change your opinion, as your opinion is your own mind's way of perceiving something, and perception is an extremely hard thing to change.
The purpose of arguing is pointless, and who gave you the right to question someone's perception or try to alter it to match your own way of thinking, as your own way of thinking (to everyone) seems like the right one.