Americans cannot fathom just how much soccer there is to follow outside the US, and likewise, foreigners cannot fathom just how much football/basketball/baseball there is to follow inside the US. This basically makes it impossible to be both an American sports junkie and a soccer junkie. Just actively following college sports will keep you full from late August to mid-June. An MLB diehard will have games almost every day even through that time period. NHL/NBA playoffs from April to June are cinema. And that's not even touching the behemoth that is the NFL. Diehard soccer fans are real in America, but they're mostly immigrants or hipsters, so they don't regularly intersect with mainstream American sports culture. Tuning in to the USMNT for the World Cup or Summer Olympics is rational for a general American sports fan, because those big global events are the only ones really worth paying attention to, not some random-ass German minor league.