Earlier quoted context omitted.
His first comment is now -19 and his other two were -3 before I came in here. Why all the pile-on downvoting for no real reason, people? Are those comments really worth -19?
It is called karma bombing and it just proves the point. Compare it to the solution where there's a recommendation system that helps everybody involved: the ones downvoting the posts will form one cluster, the ones upvoting them will be in another. People that like stories like that will see more, people that do not will be spared from them.
About your proposed solution of "clusters": Getting people to explore outside of their comfort zone, and letting them encounter ideas that challenge their faith-based views, is actually a good thing. Insular clusters do sound "safe" but I would not assume that is a net positive.