Why negative also subjunctive

Question

If querer que is a subjunctive because it expresses wants, why is the negative also subjunctive? It expresses "not wants". Or is it because that technically also counts as a want? I remember reading that if you have a negative of a subjunctive it becomes an indicative

Silvia Píriz · Accepted Answer

Hola y g.
The key idea is that the subjunctive isn’t just about “wants” vs “not wants”, but about subjectivity (things like wishes, doubts, emotions, influence, etc.). When you say “quiero que…”, you’re expressing a desire about someone else’s action, so the subjunctive is used.
When you make it negative — “no quiero que…” — you’re still expressing a will or influence over another person’s action, just in the opposite direction. You’re not removing the subjectivity; you’re still stating your preference (in this case, that something should not happen). That’s why the subjunctive remains.
For example:
Quiero que vengas → I want you to come
No quiero que vengas → I don’t want you to come
Both sentences express a personal stance about someone else’s action, so both trigger the subjunctive.
The idea that “a negative subjunctive becomes indicative” doesn’t apply here. That change only happens in different structures (for example, with verbs of certainty vs. doubt: creo que viene vs no creo que venga).
Hope that helps clarify it.
Saludos
Silvia