(Huh, I wonder why I had you blocked? Odd.)
Anyways: my initial point was that it's a very commonplace term in the US - so much so that it invites an unflattering conclusion about that user for encountering a primary school term so rarely that they're lead to think it's uncommon. You're right though, I was commenting right after waking up and misunderstood grey_matter's comment as being a reversal of the idea to reflect on me somehow (yeah, clearly wrong); it was the "sportsball" thing that threw me, I haven't seen that used unironically since the blood-soaked night when we purged the Big Bang Theory fans.