Why was barnett newmans painting cathedra attacked in 1997

The second and third events in which a Newman picture/art was destroyed were conducted by the very person, at the very museum. March of 1986, Gerard Jan Van Bladeren stepped into the Stedelijk Museum in Amsterdam and with the help of a box cutter, he tried to cut eight holes into Newman’s painting "Who’s Afraid of Red, Yellow and Blue III".  Van Bladeren was a mentally-disturbed pessimist artist who refused to accept contemporary art.