A multi-layered symbolic impasse is reached here. Nostromo's "No" stands for the People's first attempt to end their exploitation, to refuse service. The refusal is a "surprise" to Paquita, who immediately goes from "begging" to demanding.
On another level, because Nostromo has no gold, it is a gift he cannot give
even if he wanted to. I.e., rulership is not a power the People possess, that
they could confer upon the Ruler. If the People had rulership, they would not
be the People, they would be the Ruler; the People are by definition those who
are ruled. This notion runs directly counter to the Enlightenment idea in which
rulership does originate with the People and is voluntarily conferred
upon government by them. In the pessimistic view of Nostromo, rulership
is by definition one-sided and oppressive. The People have no gold and never
did.