I think that the GB must actually be aware on some level deep down, in the purely logical part of their brains, that the teachings and policies of the WTS (including themselves and their founding predecessors) have all along been bogus at least, and even dangerous and deadly at most. This has indeed resulted in many deaths due to policies regarding blood and organ transplants, as well as victims of rape, severely injuries, murder, and suicides regarding political party cards (Malawi) and even alternative military service (prison rapes).
But the hard and simple fact is that they just don’t care. The GB has been painting itself into a corner since the get-go, and they are not too keen on changing their established status quo on things like celebrating the holidays, birthdays, or even beards for men and microphone handling for women. Their attitude has always been, “Tough. Either snap completely into line or we’ll kick you out. Oh, and of course we’ll take your family away from you too.”
The whole GB/WTS thing is really just a sectarian hierarchical bureaucracy, which will always put their own interpretation and rules above people’s basic welfare, just like one would expect of any such cold, self-serving, man-made religio-political-corporate machine.