Actually, the WTS is right to say that a prophet need not necessarily predict the future to be viewed as such. What made a person a prophet was speaking in Jehovah's name, claiming to have seen divine visions or being given divine dreams. Many times that did involve predicting the future, but sometimes it was declaring the prophet knew Jehovah's will and thinking about a certain matter.
" 'They have visioned what is untrue and a lying divination, those who are saying, "The utterance of Jehovah is," when Jehovah himself has not sent them, and they have waited to have a word come true....Therefore this is what the Sovereign Lord Jehovah has said, " 'For the reason that you men have spoken untruth and you have visioned a lie, therefore here I am against you,' is the utterance of the Sovereign Lord Jehovah.' " --Ezekiel 13:6. 8
When other religionists promulgate false teachings and doctrines, the WTS is quick to condemn them. When the Society engages in exactly the same behavior, it says that its falsehoods are 'incomplete understandings', 'old light', and 'unrealized expectations'. And they presume upon God himself to overlook such errors because the mistakes occurred due to zeal to see God's purposes fulfilled.
In the end, as others have pointed out, it is the blatant hypocrisy the organization engages in that is so disgusting. They think mercy will be extended to them while simultaneously denied to others when all involved have made the same errors. For me, this is another reason why I don't want anything to do with organized religion again for as long as I live. There is no doubt that religion has done some good in the world. Even the WTS can say that it has effected positive changes in the lives of many people. But that doesn't negate the fact that they have done a great deal of harm.
The WTS insistence that it is the "faithful and discreet slave" invested with authority over all in its organization by Christ himself is a lie. That lie has led millions of people onto a path and way of life that is nothing more than a dead end. That path is littered with wasted lives, wrecked families, ruined friendships, and growing disillusionment among its membership. The cited passage promised a day of reckoning for Israel's false prophets. I can only hope that the same will be visited upon the WTS.