some things that baffle me

Publishers are under siege, and the barbarian heathens are demanding that Traditional Publishers (TP) justify their existence. I'm not a barbarian heathen, but I can sympathize with some of their positions on this complex topic.
One of the biggest reasons trumpeted by the stalwart defenders of traditional publishers is this: We have editors! Good ones!

Yes. No argument there. You do. Track record and all that. But there's a logical conundrum that's been itching me about this. This blog is my place to scratch. Publicly.

Agents tell writers to hone and polish, polish and hone, until your book is unrejectable. Join critique groups. Eliminate adverbs. Revise it nineteen times, then nineteen more. Read it aloud into a recorder and play it back under a harvest moon at midnight, taking notes with a lucky pen. Rinse and repeat. Then, when it's absolutely positively inescapably incapable of being rejected... then--and only then--query an agent. And the agent gets you in with the publisher.

Where you can finally get The Editor Your Book Desperately Needs (TEYBDN).

Presumably, your book needs this editor because you are a clueless barbarian heathen who is just so cute to think you can write an actual publishable story.

No, no, sorry, that just slipped out. I didn't mean it.

Presumably, your book needs this editor because without this editor your book will suck.

Here's what really baffles me. Conventional Wisdom (CW) would appear to be telling us that editors can't write, and writers can't edit. Only together, through the magic of a Publisher (P), can a book worthy of public presentation be created.

I mean, because, if editors could write, they'd just... write. Right? They'd create their own stories, then edit them. And there would be no need for the barbarian heathen hordes to write anything. Or, for that matter, for literary agents to exist.

So we must conclude that editors can't write. (It makes as much sense as the initial presumption that writers can't edit.)

I, for one, do not get excited by the prospect of my stories being edited by someone who can't write.