This is something you see often nowadays, especially on social media. Activists get some controversial policy approved, or censor some already-existing content. Yet if you protest it, you get the "dude why do you care" fence-sitters. They'll tell you that it doesn't matter that much and that both sides are silly anyway. Often these people are in complete support of said policy/censorship, but if you point it out they'll just tell you that those extremists don't represent them (because they're the enlightened "centrists", of course), and you get nowhere.
I feel like this is a big problem. How do you deal with this?
They're just stupid people. Or people with a normalcy bias that is pathological.
They are saying that reason will have no affect on them. Unfortunately that only leaves force, or the threat of force. Fortunately they will never think about it that deeply.
You have to treat them like a sheepdog treats sheep. Bully them to where you want them to go.