Your objections are sensible enough... I have, in fact, considered all of them before, but after honest reflection I think Yoshie's position does appear absurd.
> Whether people think something i justifiable arguably does bear on whether
> it is justifiable.
If I'm interpreting you correctly, I think this claim is probably too strong. What people think is justifiable may be (and probably often is) indicative of what is justifiable (just as the entirely factual empirical judgments people make generally reflect reality), but it is in no way determinative of what is justifiable. The causal arrow points in the other direction.
> whether something promotes happiness or desire-satisaction obviously
refers to
> what we think.
What we think will best promote our happiness or satisfy our preferences to the fullest degree often fails to do so. And, in my limited experience, sometimes others really do know better.
> Moreover, Yoshie is referring to a principle
> that you, with your White Man's Burden paternalist
> arrogance, don't acknowledge, that the opinion of the
> people affected matters most.
Any left-liberal rejects this principle (wittingly or unwittingly) with regularity, for the "masses" cannot be said to support our positions in any unequivocal sense (except, perhaps, a counterfactual sense).
-- Luke