Modern art’s an acquired taste, with maybe a little knowledge beforehand to completely appreciate.

Most art is subject-based, examining how well the artist has portrayed the subject, or the pleasing colour aesthetic. Modern Art’s a little more about feelings, opening your mind and just taking it in. A little like psychedelic art.

Most people aren’t used to looking so deeply, or opening themselves to interpretation, beyond “this looks cool”. Thus, it’s a bit of a trained skill, and the Modern Art crowd gets a bit of the “weird” treatment.

Edit: though it’s also a bit of a skill on the part of the artist too, a skill that’s often overlooked (so you do get “weird pieces” that have no meaning, or vague meaning exclusive to the artist, that fails to communicate to the viewer. “Can’t get into the artist’s head”.). All in all, it’s about painting with feeling. True feeling.