Faultline does not make a habit of covering the revolving door of executive ins-and-outs, as we prefer to look at the bigger picture. But when we caught wind that the board of directors at Plume, the WiFi cloud management specialist, has pushed out longstanding CEO Fahri Diner, we had to dig deeper. Diner’s abrupt departure signals unrest in the camp, with Plume clearly under pressure to deliver results and take the WiFi venture in a new direction that Diner evidently did not agree with. In our own experience, there is not much that Diner did agree with, unless it aligned absolutely with his fierce and broad vision for the future of WiFi software—one that was far bigger than many gave…