I wonder if Rutherford's bombastic, polemical approach was basically a marketing ploy. Although that style was retained for a while after his death. The JWs were actually banned by the Australian government in 1943, a year after Rutherford's death. The official reason is that they were a security risk (they owned radio stations back then, and some of the news reports were a bit too generous with information regarding ship deployments, etc.), but they were basically being a pain in the arse, denouncing everybody (Catholic bishops by name, the government). The government eventually got pissed off and banned them.
Interestingly, they weren't unbanned by their usual appeal to freedom of religion. The government didn't think that Section 116 of the Constitution applied. They allowed them to be unbanned because they believed that their application of the Security Act was overzealous.