People are still people, their methods haven't changed, they have made some good decisions from a corporate perspective as well. I think they are here to stay people.
I don't think even a mass exodus would extinguish them. Just looking back at their history, the 1925 debacle would have made any sane person walk away. David and the other ancient worthies being resurrected to life? It didn't happen and the the nucleus that remained got more powerful and more out of the mainstream.
For some people, they have sacrificed so much and being a JW is so much of their identity that they can't leave even if they wanted to. And if they were kicked out they would do all they could to get back to "mother." Having a large membership helped them distribute a large amount of literature which helped generate income for them for a very long time. Since that model is broken and things are available online, their costs can be greatly reduced and they can survive with much fewer adherents, even if the adherents are less educated and less financially stable.