I don't know of another film for which the ridiculousness of the plot, dialogue, performances, etc, seems to neither negate nor even work against the film's beauty or the ideological critique at its base. Though supposedly set in then-contemporary Los Angeles (although the characters make a little more sense if you pretend they're Italians), Zabriskie Point is in many ways belongs to the post-apocalyptic genre. If there's something millenial to all of Antonioni's films, Zabriskie Point's vast stretches of desert landscape suggest an end to urban society, a destruction of/escape from a human population represented in the film by campus radicals, police, and businessmen. But really, the society is mostly represented through billboards and advertisements, with the human aspect - aside from the three leads - seeming almost incidental manifestations of a faceless mass of opressive capitalist society.
Filmed in a visual style closer to early 70's Altman than the Antonioni of L'Avventura and Red Desert: hand-held 35mm scope, color, lots of close-ups and slight zooms. The near-frenetic camera style indicates a different kind of relationship to his subject than in the ennui-laden trilogy, with Antonioni no longer investigating the image with such meditative intensity. The city presents nothing but surfaces, images being held up by nothing, with nothing behind them - his characters are not much deeper, but they at least realize that something's wrong. The desert offers a chance to think, where the city is all noise and ads. And the desert is where the camera starts to settle down a little bit, not exactly empty landscapes but inhuman ones.
Whatever the hippie-dippie blather spouted by the characters ("Pretend your mind's a plant. Would it be a forest or a well-ordered garden?" "It'd be a jungle." ... That's a paraphrase, but pretty close - there's something perversely admirable to Antonioni's refusal to clean up the characters' dialogue as well - how many hippies do you know who can articulate their rebelliousness without making you cringe?), the film's actual critique is aesthetic. Billboards, advertisements, brand names are everywhere, and if there's a message to the film it's that, as proven by the jaw-dropping beauty of the final scene, consumer products are more beautiful when exploding than when put being put on display or advertized, or even when being used. The city's photographed almost exclusively through the windows of moving cars, reminding me of nothing as much as Fred Halsted's L.A. Plays Itself, while echoes of the desert scenes can be found in The Road Warrior.
Watching Zabriskie Point and L'Eclisse while elbow-deep in a paper on Mon oncle, I made a startling observation: Michelangelo Antonioni is a huge Tati fan. Rod Taylor's office building in Zabriskie Point is straight out of Playtime, and his desert house reminds me, though less explicitly, of the Arpel's modernist home. In L'Eclisse, after a Mon oncle-ish episode in which a domesticated family dog goes for a romp around the neighborhood with a pack of roaming mutts, Monica Vitti whistles at a random person on the street while hiding behind a pole.