What he wrote back then in the 1960s is still just as relevant now, with the possible exception of camera shake, due to the manufacturers long since gifting us with image stabilisation technology. His "Don't shoot too much" maxim, though, is even more relevant in today's digital world which makes it easy to take lots of photos without having to worry about cost or running out of film. Shooting randomly might produce the occasional lucky outcome, but each press of the shutter should still be the result of a considered evaluation of the scene.