British sense of humour/sarcasm seems to go over a lot of heads here.

Very often British humour relies on pauses/silences and facial expression for effect. The 'after word' at the end of a comment is often the bit where the 'joke' comes to a climax. None of this is easy to convey here and a shared cultural understanding of British understatement and reverse irony (saying the exact opposite of what is actually meant) helps in an understanding of the way we speak.

It's preferred by those with a broad vocabulary to the stream of foul language that passes for commentary in some places.