Hold on, that begs the question -- how do we know who deserves? that is the problem.

The whole thing has a circular dependency: if ranking acts as a filter, then higher rank means more readers, and that in turn means more upvotes and so a higher ranking. It is probably not so much the top being undeserving, but that deserving stuff gets missed.

This seems to be a fundamental weakness in all similar 'ranking' systems, but I am not sure of the full character and implications...

(There is certainly a substantial component of being an automated system of 'social-proof'. And the filtering can never be entirely effective: if you show everyone only the good stuff, the filtering would not get done at all.)

The advantage here is that pg is giving an advantage to high averages, not high point totals. So there's less incentive to be a reddit/digg style poweruser looking for one upvote on thousands of comments, and more incentive to say something truly insightful from time to time.

Alternative, it keeps away those who deserve to get rich but cannot overcome the artificial market barriers.

Exactly, in this, the rich only get richer if they continue posting valid comments.

Otherwise they get poor real fast.

No, they get poor based on how many previous comments are being averaged in.

So someone with a huge number of highly rated comments, could make a lot of dumb comments before it started hurting them.

I'm sure pg will come up with an appropriate formula.