This summer’s North American World Cup, a month-long extravaganza that smashed records for viewership, attendance and revenue, seemed like the culmination of soccer’s long campaign to tap in to the abundant wealth of the U.S. In fact, soccer’s world governing body was just getting started. On Tuesday, FIFA, a Swiss nonprofit, unveiled a stunning plan to spin off the commercial rights of its most popular competitions into a private company and sell off a roughly 20% stake to investors that valued the venture at $20 billion. But on Thursday, a furious backlash led European countries to announce a boycott of…