The architect Zaha Hadid, who died in Miami last Thursday at the age of 65, was one of design’s great optimists. Only an optimist could dream up the billowing curves of Azerbaijan’s Heydar Aliyev Center, which sprout from the ground, rise like sine curves, and blend into one another without ever meeting at right angles, and think “Yes, this building can live unburdened by earth’s gravity.” Only an optimistic could spend decades drawing fantastical jagged futurescapes—impressive works of art in their own right—while breaking ground on precious few projects. Only an optimist, one imagines, could make headway in a male-dominated…