>Publishing costs are far, far lower than they used to be, but good proofreading and style-guide checking still takes time too.

Absolutely, 100% agreed. Perhaps this was lost in my confrontational tone, but I agree that academic journals should be paid something.

I'm mostly opposed to paywalls, followed by the amount we're paying.

Where I partially disagree is in the fact that the editing tasks you describe are increasingly offloaded to the submitter.