I think we're basically in agreement.

The last section of my comment was indicating that I value humanity/the-future for its own sake, in addition to cooperating in iterated PD. I estimate that The-Rest-Of-The-World's welfare makes up around 5-10% of my utility function. In order for me to be maximally satisfied with life, I need to believe that about 5-10% of my efforts need to contribute to that.

(This is a guess. Right now I'm NOT maximally happy, I do not currently put that much effort in, but based on my introspection so far, it seems about right. I know that I care about the world independent of my welfare to SOME extent, but I know that realistically I value my own happiness more, and am glad that rational choices about my happiness also coincide with making the world better in many ways).

I would take a pill that made me less happy but a better philanthropist, but not a pill that would make unhappy, even if it made me a much better philanthropist.

Edit: This is my personal feelings, which I'd LIKE other people to share but I don't expect to convince them to.