If you don't care about anything good [...]

This seems to presuppose "good" being synonymous with "pleasurable conscious states". Referring to broader (and less question-begging) definitions for "good" like e.g. "whatever states of the world I want to bring about" or "whatever is in accordance with other-regarding reasons for actions", negative utilitarians would simply deny that pleasurable consciousness-states fulfill the criterion (or that they fulfill it better than non-existence or hedonically neutral flow-states).

Ord concludes that negative utilitarianism leads to outcomes where "everyone is worse off", but this of course also presupposes an axiology that negative utilitarians would reject. Likewise, it wouldn't be a fair criticism of classical utilitarianism to say that the very repugnant conclusion leaves everyone worse off (even though from a negative or prior-existence kind of perspective it seems like it), because at least according to the classical utilitarians themselves, existing slightly above "worth living" is judged better than non-existence.