Once upon a time, before “The Sopranos” broke the monopoly, PBS was America’s primary source for prestige television. With little competition, the network perfected that brand, as exemplified by “Masterpiece Theatre,” an oracular phrase used without irony and with a kind of innocence. The network’s costume dramas might let you commune with genius, the logo hinted: they’d improve and elevate you, like a lecture at the 92nd Street Y. But, as TV drama grew out of its insecurities, the PBS lineup, despite small charmers, like “Call the Midwife,” began to seem stuffy, snoozy, and rather silly, an artifact of a time when the medium had to put on airs. “Wolf Hall,” the BBC adaptation of two Booker Prize-winning novels by Hilary Mantel, looked ominously like the same old, same old:…
