So, I had been maintaining a position of not muting anyone on Stacker News. In part, that's because I don't want SN to become an echo chamber like so much of the rest of social media. I also don't want to risk missing out on something valuable that someone has to say, just because I don't like them.
As I hope is clear to everyone here, and my record is fairly abundant, I'll engage on just about any topic with just about anyone. I've had many civil disagreements with folks (as well as some uncivil ones): sometimes I change my mind, sometimes I don't, but I do always listen to what the other person said and try to understand where they're coming from. I don't argue to win (shifting the goal posts when the other person makes a good point or simply ignoring it), but rather to learn.
High-level civil disagreements are one of the things that sets Stacker News apart from the rest of the internet.
What finally got someone muted was not their opinion (which I do disagree with), but their conduct. We had gone through the same tedious argument several times and the person never engaged with my points, but just kept repeating their assertions. When they attempted to start the same argument again recently, I told them I wasn't interested in rehashing it with them and they could go reread our past exchanges to see what I think. Rather than respect my wishes, the person belligerently insisted on pressing their argument. When I set my terms for continuing the conversation (read our past exchanges and bring up something new), they resorted to name calling. Mute.
As much as I enjoy talking about stuff and having disagreements, I don't owe anyone my time or attention. If someone tells me that they're sick of talking to me about something, I will drop it (or I will at least acknowledge that I should have). I expect the same courtesy from others. Have some respect for the person you're interacting with, if you want them to interact with you.
Have whatever opinion you want, but argue it in good faith and be respectful.