Jesus believed that familiarity breeds contempt.! Not only that, Rutherford was terrible at Scrabble and he didn't know his tetragrammaton from his gramaphone.The JWs' have brought what they think of as God's name into disrepute and are not hallowing it at all by uttering a load of nonsense from door to door.
Why Jesus didnt address the Father as Jehovah?
The last two replies don't even make sense. The issue has nothing to do whether it was disrespectful to call the Father by Jehovah because Jehovah is not a name its an Attribute or Tilte of God!
Jesus does address Jehovah, Yahweh, etc not only as Father but also as "my God".
As for the actual word "Jehovah", it predates the existance of the JWs. I am sure you have researched the origins so I am not sure why you are posting this as a subject.