May 26, 2021, 5:00 a.m. ET Credit...Greg Baker/Agence France-Presse — Getty Images Opinion Columnist Tim Cook, Apple’s chief executive, is unflappability personified. When facing tough questions from investors, journalists or lawmakers, Cook tends to speak with the sparkling precision of an iPhone’s diamond-cut edges — slowly, commandingly, in an elegant Southern drawl that conveys exactly the sort of finality you’d expect from the head of a $2 trillion tech titan. Last week, though, Cook might have felt a bit like a spinning pinwheel under the polite yet relentless interrogation of a Federal District Court judge charged with deciding whether Apple is a ruthless monopolist. In the process, the judge, Yvonne Gonzalez Rogers in Oakland, Calif., highlighted a scourge affecting just about every Apple customer and the software developers who want to build apps for them.