Refusing to settle when offered a decent sum would be a huge risk. All of these child sex abuse cases so far have settled, because settling is the sensible thing to do, if the offer is sufficient. If Watchtower offers you millions, and you refuse to settle, what happens?
Best case scenario is that Watchtower is found guilty and you receive an even larger amount in damages. But in the end, all that happens is that Watchtower pays out. The GB don't go to jail. It is a civil case, not a criminal one. There is bad publicity for them either way, so forcing them to finish the trial does not achieve a great deal more than settling would. Granted, there would be no gag order, but it is difficult to know how much difference that would make.
Quite likely though, if you have a strong case, you win, and receive a lesser amount than you would have if you'd settled - is it worth the trauma? If your case is not watertight, and Watchtower somehow get off on a technicality, you have to foot the bill and are left completely and utterly destitute. For most people, it is simply not worth the risk. If sufficient people sue, and settle, it will bleed them dry, and the victims get their due compensation.