> You can just quietly make your argument and shut up.

This is generally the right approach, unless you're on the hook for the consequences of whatever the group decides. Continuing to argue a point that you've already made isn't likely to change any minds that weren't open to it the first time you said it. I think that's even in the HN guidelines.

If you're the one responsible for a decision, listen to what others have to say but if you still feel strongly that your contrary view is correct then go with that and live with the responsibility.