Even without total utilitarianism, increasing the population may be desirable as long as average quality of life isn't lowered. For instance, increasing the amount of R&D can make progress faster, which can benefit everyone. Of course one can also think of dangers and problems that scale with population size, so it's not a trivial question.
r/Fitness does a weekly "Moronic Monday", a judgment-free thread where people can ask questions that they would ordinarily feel embarrassed for not knowing the answer to. I thought this seemed like a useful thing to have here - after all, the concepts discussed on LessWrong are probably at least a little harder to grasp than those of weightlifting. Plus, I have a few stupid questions of my own, so it doesn't seem unreasonable that other people might as well.