I almost left during the year of the US primaries as the news was majority political and simply more garbage, so I'm glad that got cleaned up.
Often I don't have anything "more" to say on top of what has been said, so I wont add noise. That may be a common thread with lurkers. When I do have a unique perspective and I feel adds value and not noise I may comment, keyword is "may".
I couldn't care less about karma, popularity, social scores or the like (just more garbage). As long as this site and it's users continue to provide value to me by filtering and aggregating tech news I will continue to use it.
Just another lurker mooching off of non lurkers. Selfish yes, but it works.