It’s not that pg is a particularly heavy user of the phrase — I counted just 46 unique instances in a simple search of his site — but that he knows how to use it. He works it, gets mileage out of it, in a way that other writers don’t.
[I]t turns out that “it turns out” does the sort of work, for a writer, that a writer should be doing himself. So to say that someone uses the phrase particularly well is really just an underhanded way of saying that they’re particularly good at being lazy.
Further, Somers believes readers are disarmed by it:
Readers are simply more willing to tolerate a lightspeed jump from belief X to belief Y if the writer himself (a) seems taken aback by it and (b) acts as if they had no say in the matter — as though the situation simply unfolded that way. Which is precisely what the phrase “it turns out” accomplishes, and why it’s so useful in circumstances where you don’t have any substantive path from X to Y. In that sense it’s a kind of handy writerly shortcut.
Ethan Fast did a bit of analysis to find instances where this theory breaks down a bit:
Not to put too fine a point on it, but it turns out that these claims of hacks and benign disingenuity amount to something so small that I would call it nothing (albeit, a very clever nothing).
I sat through a number of presentations recently. I couldn’t help noticing the phrase “it’s worth mentioning...” It marks a pivot point in conversation. Whenever it’s mentioned, I stand at attention, assuming everything that came before will pale in comparison to what’s about to be said. It turns out, some things are just worth mentioning.