Very cool, if true

"someone liked it, and it was edited" isn't a perfect system. But it's something

Indeed...

you said yourself that the Kindle charts are a mess at the moment.

I was thinking more of something like metacritic combining user ratings and critic reviews rather than sales charts.

there will be a slippage of people from the "Just about making it as a full-time author" category down into "part time author with a job to support them".

There may well be such a slippage but the more pronounced phenomenon will be the much much larger class of people who consider themselves an author (IMHO).