Why was this fêted Mexican painter left out of the canon?

Think of a Mexican painting, and chances are you’ll conjure up an image of an eyebrow-knitted Frida Kahlo, or a riot of exotic figures by her husband Diego Rivera, or a brightly coloured guitarist by Rufino Tamayo. What you’re unlikely to have in mind is an earthy landscape with a dusty road leading to a nascent city, dotted with hyper-real plant life, and an eagle soaring under a vast, cloudy sky.