There are probably two stronger objections to average util along the lines you mention.
1) Instead of talking about killing someone with net positive utility, consider bringing someone into existence who has positive utility, but below the world average. It seems intuitive to say that would be good (especially if the absolute levels were really high), yet avutil rules it out. To make it more implausible, say the average is dragged up by blissfully happily aliens outside of our lightcone.
2) Consider a world where there are lives that are really bad, and better off not lived at all. Should you add more lives that are marginally less really bad than those lives that currently exist. Again, intuition says no, but negutil says yes—indeed, you should add as many of these lives as you can, as each subsequent not-quite-as-awful life raises average utility by progressively smaller fractions.
There are probably two stronger objections to average util along the lines you mention.
1) Instead of talking about killing someone with net positive utility, consider bringing someone into existence who has positive utility, but below the world average. It seems intuitive to say that would be good (especially if the absolute levels were really high), yet avutil rules it out. To make it more implausible, say the average is dragged up by blissfully happily aliens outside of our lightcone.
2) Consider a world where there are lives that are really bad, and better off not lived at all. Should you add more lives that are marginally less really bad than those lives that currently exist. Again, intuition says no, but negutil says yes—indeed, you should add as many of these lives as you can, as each subsequent not-quite-as-awful life raises average utility by progressively smaller fractions.
I think you meant ‘avutil’.