zlacker

If they are active, then by definition they are involved in the site (though not necessarily by voting, they could also submit stories and make comments).

If they're not active, why should HN assume otherwise?

If there really is nothing good to upvote, then I don't see what the adoption of the system you propose will do, as the extra proxy votes won't be used (there's nothing good to upvote, remember?).

The other major problem with your proposal is that it will be very open to gaming the system. Users could just create sockpuppet accounts to give their primary account the votes of the sockpuppet accounts.

Of course, even with the present system users can create sockpuppet accounts. But at least with the present system, voting from the sockpuppet accounts has to be done manually rather than automatically being aggregated in to one account by HN itself.