[evanwise]

Even if we accept their motivations at face value (which is naive), it's a totally incoherent morality. There are infinitely many future states with trillions of of lives. Which one is the one we attach moral value to? If it's all of them, then every single decision you make is equivalent to killing infinitely many future people. If it's one particular future state how do we decide which one? (I am not, of course, saying that you shouldn't value making the future better, just that applying this specific kind of utilitarian calculus to future humans is childish nonsense.)

[imtringued]

Yes it is basically the classic expected value problem but we don't know the outcomes or their probabilities.