Good points doubtfull1799 and I personally believe it has a lot to do with their name Jehovah`s Witnesses and their main publication "The Watch Tower Announcing Jehovah`s Kingdom" and their emphasis on that name Jehovah.
Christians in general throughout the earth have been conditioned through the Centuries to accept that Jesus Christ is the King of Gods Kingdom and that he is the one to worship .Jesus is the one that gave his life under suffering and is the central point of Christianity." The name of Jesus is to be above every other name in heaven on earth and under the earth." according to the New Testament.
Jehovah`s Witnesses came along and preached an "Old testament God Jehovah" and have never ever done so effectively enough to compete with what Christendom has accomplished over the Centuries.
Jehovah`s Witnesses main accomplishments have come from poaching Christendoms non attendees ,those ignorant of their faiths beliefs ,and those that are most vulnerable in society with few exceptions.
They have had zilch success by comparison in the non Christian world .