What I know my JW aunt became one of them in the 50's when the communist repression was the hardest. She came from bourgeois family which pretty much undesirable social class. Women like her were sent as a forced labor in factory where she met JWs and offered her bible studies. She became one.
My parents were deeply anticommunist and antisoviet, and WT offered a hope in era when people lost hope after brutal suppression of the Prague Spring. 1960's was decade of relative freedom and prosperity in Czechoslovakia, people could travel abroad, censorship was abolished, living standard improved that my parents had house, car, summer cottage; and they did not have to be associated with the communist party. In that decade, communists did not care about loyalty as long nobody crossed their business. This changed with invasion and subsequent occupation of the country in 1968. My dad was supportive of the changes in the 1960's and this was the end for his career. My mom did not like any communist, even the reformed liberal ones like Dubcek, so she was not purged of her job. My JW relatives offered a vision of new world when Jesus will arrive and will destroy Soviets in 1975. Soviets shoot at my dad in 1968, and the revenge from mighty God in couple year later looked sweet to him. But my dad never had enough time to dedicate to full bible study with them and this dragged on, but eventually only my mom got baptized for the 1975 hype. I met a lot of men in my KH who were like my dad, and due political changes they find WT teaching interesting. In 1968-1972 there was huge spike of suicide because people feel hopeless. It was oppressive era especially in comparison to freedom people enjoyed in the 1960's.
WT prey on misery of the others. If WT would say my parents in 1969 that Armageddon will be 40 years later, they would not have joined. However, 1975 was just couple years away...