The danger of letting people build protective walls around themselves is that they will be tempted to do just that.

I agree that this is a danger. However, I would argue that giving each user the ability to avoid other users is a critical component of civil discourse. If (as in meatspace), you know that I can choose not to interact with you, then it signals that when I do, I have made a conscious choice to do so; I give you my attention, and thus, there is the groundwork for an expectation of mutual respect.

While the MSM tends to consider the counter to every opinion to be worthwhile by the mere fact that it has been voiced, intellectually honest discussions place a heavier burden on all parties.

Just as dangerous as an echo chamber, is a chamber filled with opinions that will not be changed. The magic of intellectually honest discussion is that your mind can come out different than when it entered. IMHO when we speak of honest discourse, we often focus so much on the rights of the speaker, that we overlook those of the listener. A honest exchange happens when both parties risk something to make it happen. Thoughtful people want their opinions to be considered, not only heard.

Thus, we don't provide these functions for intellectual comfort, but to support mutually-established foundations which are requisite for intellectual exchange.

Once again, thanks for this piece.