Websites are used in different ways by different folks. For instance, I read Slashdot several times a week, but would be classified as a 'dead' user because I never registered and never posted a comment. To me, 'dead' has a pejorative sense that denigrates a fine use of PM: reading and learning.

Because simply browsing the Perlmonks site is a perfectly valid activity not captured by your stats, I think that the ratio of writers to readers is even more extreme that you portray it. But that is ok. If every visitor of PM felt compelled to submit a node, I think the result would be pandemonium.

I don't know of any participatory website statistics, but I suspect they would be similar to PM. To answer your question, ask yourself: How many websites do I visit that allow participation vs. websites that I actually participate in? For me over the span of months it is hundreds vs. 2.