It might be that mutees have no idea why a poster does not want them to participate in a discussion. As cgod said here they should get over themselves and move on, but if they feel misunderstood and really really care, then the mutee should be self-fucking-reflective and go back through his previous conversations with the muter and try and figure out where things went wrong. If a person cares about being muted, then do the work, trace it back, and create an apology that is meaningful. Do the work.Would you like to reach out x?"
I like this variation on kleinbl00's excellent idea and here's why:
I will say this: when I mute someone I am on my last straw. (The count's at two and one's a spammer.) HOWEVER, if someone I'd muted reached out to me reasonably politely and asked, I would try my best to give them a civil conversation. I might have to wait on replying to their post for a day or two to calm down and accurately determine what I wanted to say, but I would recognize that the person is willing to have a discussion and potentially work things out. And because of that I would try really, really hard to honor that. I'm not saying it would always work out, but I think this adds humanity to Hubski, which is something we advocate here. I would also be really happy that this work-out was happening in PMs and not in threads. Work things out one-on-one. I've been short with users sometimes and sent them messages, "Hey, nothing personal," or "hey, sorry if that was shitty, life's eating my shorts today." Usually, if you reach out to someone in person, they'll be more understanding.