This is too dismissive. Reddit users and communities have history, links, upvotes etc, which is hugely valuable, and it should be possible to implement a PageR

This is too dismissive. Reddit users and communities have history, links, upvotes etc, which is hugely valuable, and it should be possible to implement a PageRank-type system to separate the signal from the noise and surface the most valuable results. Now that noise is still considerable, thanks to karma farming etc (did you know you can buy and sell Reddit accounts?), but humans can usually tell apart the shills from the legit posters and automating this doesn't seem unsurmountable if Reddit cared. Which, oddly, they don't seem to.