Charitably not addressed in the article is that the paintings, to judge by the single example provided, are terrible:
Where to start? The application of paint is perfunctory at best, and in a way that's neither charming nor interesting. The composition is clumsily lopsided, with its feeble black vertical struggling unsuccessfully in a losing battle with leaden horizontals.
Let's relieve our eyes and look at a successful abstract painting which uses the exact same color scheme, Clyfford Still's 1948-C, a famous canvas which Mr. Berger may have enjoyed seeing at the Hirshhorn :
Not to imply that a Mr. Berger saw the Still painting and said, incorrectly, "Hey! I could do that!" or anything. Heavens, no!