You can connect without allowing access to camera.
I don't know if the org has nefarious reasons, but it doesn't seem unusual to have video conferencing applied this way. I'm not a fan of the cult, but I'm sure JWs like to associate and see one another. My wife has been logging on so far via phone so that she doesn't have to dress up.
I know it helps the religion to maintain control, I'm not sure they cognitively think of it that way, I think they view it as a way to associate, I think they truly believe all the way to the top that they are God's chosen people, so while actions are cultish, I doubt they see it that way.
From the outside looking in, we know it's a cult, or at least a very controlling group.