I don't think that art without meaning is decoration, nobody makes art that doesn't have a meaning, it always has a purpose of why it's made or an idea that created it. By having an idea or an inspiration for a piece of work than it has a meaning. Look at work by Picasso, his geometric designs look like they have no meaning but does that mean his work is just decoration like wall art? Or graffiti, it might look like it doesn't have meaning but usually the artist has a hidden message that means something to him/her. One can physically not make a piece of art without having inspiration behind it that creates a meaning to art.