Because when hockey was invented, after the team won, Lord Stanley used to stand up and salute them by "pointing" his two abnormally long index fingers straight into the sky and towards God. The players used to remark that it was "nice to be able to get two points tonight from Lord Stanley", which evolved over time to the points system as we know it today. If the event of a tie, the skaters would often remark, "at least one of the points from Lord Stanley was for us tonight", hence the distribution.