A lot of writing rules are of the "follow it until you know how and when to break it" variety. That way if you never learn how to break them correctly, your writing is still a lot better than it was. It's no surprise that studies of writing already known to be good will find much rule-breaking, as one is not surprised to find race cars on a race track moving faster than we'd want any car to, ordinarily.

> A lot of writing rules are of the "follow it until you know how and when to break it" variety.

Prescriptivists never seem to add that clarifying nuance to their advice though.

> That way if you never learn how to break them correctly, your writing is still a lot better than it was.

That assumes their advice is good in the first place - when professional linguists call it trash, I'd have to wonder if it is.

> Prescriptivists never seem to add that clarifying nuance to their advice though.

They often do, in my experience. AFAIK it hasn't been common to attempt any kind of real, strict prescriptivism in English since the middle of last century (yes, I'm sure a few examples exist). These days it's mostly "write like this—until you know better" or "avoid X if your audience is Y, for such-and-such reason".