By not saying or doing anything about it, that would mean that yes you are passively supporting the status quo.
E.g. if you are for gay rights and yet you say nothing when people around you use the word gay as a derogatory term, and you say nothing when someone says that gay people are just sick, and you do nothing to show that you are for the equal rights of gay people, you are, in your passivity, in your silence, allowing homophobia to go unchallenged around you. Hence that is essentially passive conservatism, not in the sense that you are actively trying to keep the status quo going, but because you are not saying or doing anything at all to change the status quo.
It's kind of like Newton's 1st law of motion - without resistance, things will continue in the direction they're going. If you choose to act in any way to resist that trajectory, you are already not being passive in your politics anymore.
What Ishina said. There's conservatism as it is usually understood, and there's what you're talking about. A person may support change in principle, yet still not act (for a variety of possible reasons).
Devious, treacherous, murderous, neanderthal, sub-human of the West.