I don't think it's an American thing, so much as an ESPN thing. They do well in the loud, manic, sportscenter type shows and the in-depth 30 for 30 type shows, but they seem to have trouble with live sports.
The NBA coverage on ESPN is soporific at times and the NFL works because Tirico keeps it simple and Jaws provides real insight.
All the other live sports coverage tends to be either overwrought or boring