Danny,
I see it as a moral imperative.
1. You offer them the truth of reality as general human society struggles to comprehend our Universe. Given how far we have to go yet, it's no comfort blanket you're offering them but it's real!
2. It is the duty of every human to think (learn, rationalize, ponder, evaluate, debate, etc...) for themselves to the best of their ability (I'll even give Ms. Rand a nod in this regard!) even though it's uncomfortable .
3. Each of us have an individual responsibility for our actions.
4. Yes, you're probably not going to change the world, but that arguement could be extended to AIDS donations or emergency relief- Even small actions can have effect whether it's immediately measurable or no.
You can have an effect just by being the best human you can be (especially if you're in a smaller community). You don't need to be confrontational (it doesn't seem to work anyways) in trying to help other JW's. The best argument I 've found that makes'em think is the statement: I just wanted to be honest and I couldn't do this in the Organization. It will make them think even if you don't see any results for some years.
W.