Your comments reflect a position held by many cult apologists concerning "new relgious movements" (NRMs). However, many groups or movements called "cults" are not based upon religous beliefs and therefore cannot be considered NRMs.
All of this is discussed in depth at the Cult Education Institute database.
Robert Jay Lifton wrote a paper in the 1980s and essentially established what can be seen as an objective structural and behavioral based nucleus for the definition of a destructive cult.
The JWs fit well within the definition in the early stages of their development under the absolute authoritarian control of Russell (once known as the "Russellites") and Rutherford. After Rutherford power devolved from one charismatic leader to a governing body. Today JWs can be seen as a destructive authoritarian group, but not a destructive personality-driven cult with an absolute leader per Lifton's definition.
Likewise Mormons went through a similar history. After Joseph Smith and Brigham Young power devolved into a church government. The Mormons have devolved power much further than the JWs and though still somewhat controversial and not part of mainstream Christianity, they don't today fit the definition of a "cult."
Anticipating your questions, Judaism, Buddhism and Christianity do not have as historically well documented of an early history as JWs and Mormons. Not as much is known historically about Abraham, Moses, Jesus and Buddha, other than through their respective religious texts.
But there is a well accepted core definition for a destructive cult that has been around for a long time. And most, if not all subsequent definitions, simply extrapolate upon Lifton's three core criteria or characteristics.
ISKCON has not really evolved and is still seen as a destructive cult by many observers and researchers. It was never really part of mainstream Hinduism and always a personality-drive cult devoted to Prabhupada and his disciples. ISKCON has a horrible history of abuse. It's recent reforms are a response to lawsuits and legal claims that drove it into bankruptcy in the US and almost collapsed the organization. ISKCON continues to generate complaints and the behavior of its devotees is still a source of concern to Hindu and non-Hindu parents.
I hope this is helpful.
Edited 5 time(s). Last edit at 05/25/2020 09:45PM by rrmoderator.