I'm a born-in, so for me and others like me it was different. We didn't evaluate anything. We were just slowly eased into it.
It's probably different if you are an adult convert where perhaps you consider different things before you decide to join. But i think for both types the social aspect of the organization is truly the defining factor. I recall bringing a few visitors to the KH and see how everybody made them feel as if they were the center of the universe. Hugs, smiles, attention.
Even if you didn't really know what you were getting into, you felt as if you were someone special there. I think it is that social aspect that keeps a log of JWs hanging on.