sometimes it's because everyone is assumed american until indicated otherwise
so starting a comment with "as someone actually from here" can head off a bunch of "well i heard from a guy" or "i vacationed there for a week when i was 9"
one that sticks in my memory is i was once told that i "lived under sharia law" (which doesn't even make sense btw, sharia loosely means law by itself) because they had heard it on fox news
i live in fucking england lol