KitKat, I suspect it's because in the colonies we so often pronounce "was" as if it were spelled "wuz". I realize this is a rank generalization (not that I care), but people in the UK always seem to pronounce "was" so mellifluously that perhaps it just sounds better. Or maybe you're just all ignorant (o,-).

Some are born pedantic, some achieve pedantry, and some have pedantry thrust upon them.