When you say "the British should be held accountable" all those individuals are dead and gone. It's a bit Catholic to hold the children accountable for the sins of the father. Its unlikely my forefathers even had the vote at that time. So please explain how I'm accountable again?

Edit: It's clearly a subjective topic, but there are significant impacts felt the world over due to the British empire. I'm not sure you can say the same of Alexander the Great. People are directly and significantly affected to this day by the actions of the British. I guess the nature and extent of the impact would need to be decided by a court, but it'll always be an imperfect science. That doesn't mean it's unnecessary.