NEW YORK — Three years after Kevin Durant left them in free agency, the Warriors are back in the Finals and the Nets couldn’t win a playoff game. It’s a narrow view of a complicated legacy question, but as Charles Barkley reiterated Wednesday, it can stand as an argument against Durant’s placement on the NBA’s Mount Rushmore. “You know it has an effect on his legacy,” said Barkley, who was promoting his upcoming appearance at the American City Golf Championship at Tahoe. “If you go back and look, and I talked about it on the [TNT] show, LeBron has said it before — he said, ‘I had to win a cham…
