What good is preventing resumption if the world becomes Hell?
I think this question goes to the root of what RBS was trying to achieve. Golgotterath is a crash space, where meaning and morality collapse. So is it better for mankind to suffer horribly in the Inward and go extinct under Resumption? To live normal lives in the Inward, but suffer an eternity of torment in the Pit? To experience Hell on earth under a manifested Ajokli (that one seems like an easy call, but what becomes of the metaphysics of souls under a God manifested in the Inward?)? I think we're meant to grapple with these questions ourselves, although it seems clear that if Kellhus chose the second option presented above, he deviated from what the rest of the Dunyain did or would have done. We can only guess at why; he went crazy, Ajokli tricked him into it, his love of Esmenet made him do it, etc.