Null <i>is</i> wrong.  It was implemented because it was easy, as it maps directly to how object references are typically implemented in memory: <a href="http:&#x2F;&#x2F;lambda-the-ultimate.org&#x2F;node&#x2F;3186" rel="nofollow">http:&#x2F;&#x2F;lambda-the-ultimate.org&#x2F;node&#x2F;3186</a>