In their heyday, Napa Cabs were nothing like today’s stereotypical version. The flower-power vibe of the 1970s was apparent in the rough-around-the-edges, lively, vegetal, and experimental Cabs of that period. Then came the critic Robert Parker and the development of winemaking technology — two forces that influenced winemakers and consumers alike to acquire a taste for bold, high-alcohol, jammy…