Art or not?

I am not a visual art expert but I can not help but mock at these "art" I recently saw at the Milwaukee Art Museum. These examples are exactly the reason why I do not subscribe to "modern art" cause it all seems arbitrary for me. Put a black speck on a white canvas and you got art. It is bull shit as far as I am concern. Or perhaps I just do not get it? If I don't, then so be it. I would rather not get it than be a pretentious art connoisseur.