All right, I can buy that. Although it may be that a small compromise is possible: taking future people into consideration with a time discount large enough that radically different people won't muck things up. To be more specific (hence also more hypothetical), current people may insist on taking into account their children and grandchildren but not worry so much about what comes after. (Again, talking about what has to be explicitly included for political reasons, separate from what gets included via the actual utility functions of included people.) This is probably getting too hairsplitting to worry about any further. (^_^)