The only way would be to change the incentives. Shaming will do no good, as you say, or won't do much good in the long term.

We must change the incentives! The way for long term valuable content to be valued probably involves -
Lengthening payout time or creating drip faucets on locked articles based on views or under certain favorable conditions.
Considering a negative incentive for upvoting (probably automatically) an artivle that turns out to be worthless or of detracting value.

Basically we need more levers, we need more experiments!

Thanks Lex for cutting through the feelings to try to see the truth.