Reading AndyA's comments here, this is something that's been bothering me re: Google's desire to penalize spammers: how does the algo tell spam from certain writing styles or flaws? For example, people who aren't good at using synonyms have been "keyword stuffing" their papers since the dawn of academia, LOL. It's not about Google when they do it online, it's just they don't know a better style.
I know Google knows this is hard to work out with just math, and I assume that's why social is so important to them: if the algo can see that loads of people are spending time on or passing along this site that mathematically reads like spam, the algo can work out that maybe it's just a spam-like writing style and the page still has value.
And yet, I'm afraid it will always be points off for one of those writing styles the algo thinks might be spam, so someone who writes that way will need even more positive social feedback to get where they should be in the SERPs.