There are other abusive cults that have gotten away with child abuse and other immoral and illegal acts, is Jehovah protecting them too? Scientology, the Moonies, the Mormons just to name a few. Scientology is one of the worst, they managed to be classified a religion and gain tax exempt status despite not actually being a religion, use goon squads to intimidate and harass former members who speak out and keep their lawyers very busy filing lawsuits over any perceived slight. The Moonies are even more abusive than the JWs in using cult mind control, they have enormous financial power and have even infiltrated governments.
That these groups still exist is simply due to the nature of cults, they use mind control to manipulate their followers into doing what they want and have enormous power over their members, God has nothing to do with it.