It's a mercy, whether the present generation of mortals understand it or not, I would destroy them all in a heartbeat to save them and all future generations who would be born into a world of pain, conflict and death. The lives they cling to pale in significance to life in the perfect world they stand in the way of achieving. If I thought I could revert life to a garden of Eden type of utopia then I would find it extremely negligent to let anyone else be born into a fractured world of suffering.
If the mortal condition was but a choice, how many would opt to have a short lifespan, susceptibility to diseases and cancers, and the feebleness of age. People learn to cope with terrible fates because they think it is inevitable and beyond their control. If you don't sacrifice the people of the present, you condemn every future generation who will ever live to death by way of mortality so the death toll of your inaction is infinitely higher. The cycle of imperfect life can be ended, they think. I only agree with everything that I just said if it can be guaranteed that the utopia is lasting. If there's the slightest flaw in the plan which would undo the world as had happened before then yes the ascian objective is a shaky proposition.