Why so much energy

and invention in '60s music and so little in '60s art?

From the '60s onwards the nominal arts become of strictly academic interest.The contrast between the energy of the counterculture and the enervation of '60s institutionally sponsored art is striking. Just at the moment when things were heating up on streets, campuses, and music venues, things were cooling down in galleries.

The best thing that came out of modernism was so-called primitivism, but by the 1960s, primitivism in art was in abeyance. When it resurfaced in the '80s as Neo-expressionism, things weren't the same, probably because Neo-expressionism was the expressionism of artists who had learned about it in art school. Plus,  primitivism needed an ironic cover in order to be smuggled into institutional settings, so it came across as a simulacrum.

Fast forward to today and both art and music are equally boring.