Any reason given?
Think that would be the Six Nations. Don't think it is arrogance though, more like a lack of imagination.In South Africa it will be known as "The Castle Rugby Championship"
I don't think its all that bad.
the English Rugby Football Union call themselves "THE RFU"
the USPGA call the American Masters Golf Championship "THE MASTERS"
the PGAGBI can call the British Open Golf Championship 'THE OPEN"
So why can't we call the world's Premier International Rugby Championship, "THE RUGBY CHAMPIONSHIP". Its probably a bit arrogant... but who cares.