Think about how team games games are scored. The answer lies there.
If the difference between winners and losers is 10, 20 or 50 points, then if one side or the other gains or loses a few extra points purely by chance, it won't affect the outcome - the better rated team will still win. Rugby, cricket, baseball, grid iron all fit this model.
In soccer however, the difference between winning or losing is often just 1 or 2 goals. Chance plays a huge role. The better team may get some unlucky decisions or hit the crossbar or posts, and thus lose to a worse team who gets some luck. In other words, the plucky underdog still has a decent chance.
And that is what appeals to American psychology. Americans like plucky underdogs to have a chance, even if it's because of luck. This is also why Star Wars for example was a huge movie in the US (one farm boy defeated an entire Empire!) - despite being a damb squib virtually everywhere else. This rooting for the underdog is why soccer is popular in the US.
In contrast, most other countries like to focus on the beauty and skill in sport. They believe the better team deserves to win. They believe it would be a travesty if the better team lost because of bad luck. Hence higher scoring games like grid iron and rugby are popular, but soccer is disliked, even despised.