He had just been speaking about the difficulties facing the art form to which he has devoted his life. Its shrinking footprint in mass media and popular entertainment, coupled with the decline of music education. A lack of stars who can sell out houses, especially now that recording companies no longer have huge marketing budgets. High expenses, for a skilled work force protected by powerful unions, which are going up faster than ticket prices can be raised, making fund-raising more desperate than ever. The erosion of subscriptions, the backbone of companies. And his long battle to commission more melodic, less esoteric operas — which has sometimes met with resistance from composers and disdain from critics.

While he said that his immediate plans called for sailing, sleeping late and investing in an edible marijuana-truffle business that one of his daughters started in Colorado (“I’m an investor, not an eater”), he will also continue to advise the company here as needed, as general director emeritus. Still, his stepping down is a big moment — another major changing of the American operatic guard this year, following James Levine’s retirement as the music director of the Metropolitan Opera.

“David is a visionary, and he had a concept of how opera could become more American by developing an American opera repertoire, by developing opera companies that were more connected to their communities,” said Marc A. Scorca, the president and chief executive of Opera America, a service organization, who credited Mr. Gockley with prompting other companies to value new work.

Mr. Gockley, who grew up in suburban Philadelphia, caught the opera bug as a child, when he heard leading singers performing arias on television programs such as “The Voice of Firestone.” He tried to break into the business as a baritone. But when vocal struggles made him realize that he would not make it as a singer, he went to Columbia Business School and studied arts administration.