I think you just have different intuitions than average utilitarians. I have talked to someone who saw no reason why having a higher population is good in of itself.
I am somewhat swayed by an anthropic argument. If you live in the first universe, you'll be super happy. If you live in the second, you'll be pretty darn happy. Thus, the first universe is better.
On the other hand, you often need to consider that you're less likely to live in one universe than in another. For instance, if you could make 10% of population vastly happier by killing the other 90%, you need to factor in the 10% chances of survival.
Haven't had one of these for awhile. This thread is for questions or comments that you've felt silly about not knowing/understanding. Let's try to exchange info that seems obvious, knowing that due to the illusion of transparency it really isn't so obvious!