When Federal Reserve Chairman Jerome Powell speaks, investors listen. They listen as if there are fortunes to be made by guessing correctly about when the Fed might begin cutting back on the amount of U.S. government-backed debt it buys every month. They listen for the stray word that could spook financial markets. Mr. Powell’s speech on Aug. 27 proved to be unspectacular in all the ways that count on Wall Street. Nevertheless, it was a spectacle.

The people striving to interpret every nuanced statement—financial analysts, hedge fund managers, investment bankers—apparently were pleased with Mr. Powell’s performance. The S&P 500 and Nasdaq Composite climbed to records following the Fed chief’s speech, which included his observation that monetary-policy makers shouldn’t “attempt to offset what are likely to be temporary fluctuations in inflation.” Bond yields dropped concurrently with his remarks.

But for people who live off paychecks rather than portfolios, the game of deciphering Fed officials’ intentions is a sideshow that leaves them further behind. This is no way to run monetary policy. Our nation’s central bank has become too prominent, too political and too powerful.