When they were proved wrong, they covered it up. Early Jehovah's Witnesses taught that the end of the world would come in 1914. When that didn't happen, they quietly changed the prophecy in their books. All nations will see his coming. Jehovah's Witnesses deny Jesus' teaching about hell.
Nobody likes to think about hell.
But to twist Jesus' words to pretend he didn't teach it is dishonest. Jehovah's Witnesses pronounce that it is unloving and unjust for God to punish the wicked forever. Jehovah's Witnesses deny that a human being has an immortal soul at all. There is no bliss, and there is no suffering. Convenient, but certainly not what Jesus taught.