You can, but we're discussing why soccer is not popular in the US and soccer advocates keep bringing up how popular it is with kids as proof it is "popular." The point many of us are making is that kids seem to completely lose interest in soccer by middle school or perhaps a little later, whereas with other sports, perhaps they don't participate in high school but the interest is still there in terms of watching/following pro sports.
Also, some of these soccer advocates make it sound like kids playing soccer is a recent development. It is not. Kids played soccer when I was in grade school in the early 80s and now that my generation is nearing 40, you'd think we'd be at the vanguard of bringing it to the mainstream. This obviously is not happening.
Every decade since the 70s, American sports fans have heard "This is the decade soccer becomes big in the US!" And every decade, the prediction is horribly wrong. No one can dispute that, as it is a fact; you might debate the reasons, but it isn't a popular sport among adults in the US. If you like it, that's fine, but the people here insulting Americans (they have no attention span!) and their sports (NFL players are fat brutes!) in general as some sort of defense of soccer is pretty lame. We just don't find the sport exciting for the most part. Now, if you took away some of the rules or lessened them (like the offsides), THEN maybe it would be a little more exciting.