So you suggest that all people who do not post often enough do not fit into the community. And that posting often is the metric to drive? And because, in our current example, you have a higher karma per day, you belong to this community as opposed to me? But if nickb was to read this comment then you and I might both be trivial?

Finally, as a supposed 'lurker', it might serve me better not to login and just read submissions instead of participating by voting. Clearly, voting and commenting are also measures of 'being in a community'. So as lurkers stop logging in they cannot vote and then voting drops making the submission rankings either volatile or static.

I do not understand your line of reasoning.