We have three PBS stations in New York. Tonight, in pledge time, one of them has a diet show and two have cheesy violinist Andre Rieu. That is PBS’s dirty secret: They aren’t supported by high-class culture but by low-class cheese. Hey, whatever pays the bills. But why not just start the all-cheese-all-the-time channel to raise money for the real channel? Or why not just take ads? Are they really worse than Andre Rieu?