The whole argument around the necessity to preach due to bloodguilt, performing a lifesaving work and so on makes no sense whatsoever.
Of course, when I was in then it was completely logical however when you start to reason on the scale of the work, the implications for those not reached, the conflict between destroying the vast majority of people and divine justice, people being better off dying before Armageddon, what actually constitutes someone's "chance" and on and on and on then the arguments for preaching simply become ludicrous.
The only argument that has biblical backing and I don't have a strong counter argument for is that Jesus commanded his disciples to preach about the Kingdom and make disciples themselves.
If the WTS shut up about all the other arguments and simply said "we do it cos Jesus asked us to" then it would be a hell of a lot harder to deny the need to preach.