I used to mute people all of the time on Reddit if/when it was obvious that they were trolling/not being constructive, and advocated that others do the same (rather than engage them, which it seems they always did.) Unsurprisingly, that never caught on - people enjoy "engaging the troll" or arguing hardheadedly too much to consider their time spent wasted.
Conversely, I have come across users in the past that had contrasting views from mine, but that obviously cared enough about "the thing" they were talking about that they were able to present clear arguments illuminating their reasoning. I chose not to block these people, and regardless of whether I agreed or disagreed with them, our conversations were always constructive.
I guess my point is, some discussions are worth continuing, others are not. I look forward to seeing if the ability to mute here makes "muting the noise" in pursuit of meaningful discussion a more standard practice.