That’s a myth perpetuated by Christian mums during the satanic panic. Back in the 60s the hippie movement was in full swing and young people were abandoning Christianity to follow pagan religions like Wicca and Hellenism. Christian pastors felt threatened, so they came up with a conspiracy to take the word cult (which up until then had meant a small religion) and make it a bad word by association with abuse. That’s why all the historical examples of cults that predate the 60s have no association with abuse. You take an example like the Cult of Dionysus and there’s no pejorative meaning to the word.