They have the no blood transfusion rule because they have, going back to Knorr and Franz, this philosophy that they need to obey God's rules to please God.
In other words, they are pharisees in that they want to say that we are better than everyone else because we obey these rules. That's what everything is about, getting God's approval because JWs are better than everyone else.
And they feel that we have to do everything to get that approval to get life.
But they don't consider the question of How can it be a law if there are not consequences for breaking it?
People who take blood or give it continue living and then die like everyone else. So they say they won't get a resurrection. The dead are conscious of nothing, so they dead don't worry about not getting a resurrection. But yet is that something that will land someone in Gehenna? No. Because idolatry and fornication won't either.