I spent quite some time looking into the problem. The solution imo is twofold. First, yup, collapse all comments past 2nd level by default, show only top commen

I spent quite some time looking into the problem. The solution imo is twofold. First, yup, collapse all comments past 2nd level by default, show only top comments (others collapsed) on second level. Second, the same model used for HN threads should be applied to comments - not just karma, but a combination of recency and karma. Right now we are demotivated to post on 1st level of existing threads exactly because of karma accumulation for top level posts. Hence, my comment is here :) We're working on a relevant product for communities so if you're also interested in this problem, let me know.