A potential solution:

Implement a comment recommendation system. Based on comments you've liked and disliked, the system will push comments you would like to the top.

The quality of the community you see is then completely up to you. If you like poop jokes, you'll see poop jokes. If you like pedantic attacks, you'll see pedantic attacks. And if you like insightful comments, you'll see insightful comments. As you stabilize on a community you like, you can start responding to their comments, and then they too will have the chance to vote on your comments. If they like you they'll start seeing more of you, and a micro-community will evolve naturally for free.