I posted that question with Tim Grey and DDQ, and he agreed that one step sharpening is as good as the two step process.)
Yeah...and Tim is wrong (I've told him that to his face so I'm happy to state that here on the forum). Now that Tim has left MSFT and is getting back into digital imaging and digital photography, perhaps he'll learn that or not–his choice but I wouldn't bet my life on Tim's advice without doing my own tests–which I have.
No less the Thomas Knoll who coauthored Photoshop and was the founder and primary engineer on Camera Raw seems to have agreed with the concept of a sharpening workflow because that's why he chose Bruce (and I filled in for Bruce) when he wanted to improve the capture sharpening of Camera Raw. The Lightroom engineers thought highly enough of a sharpening workflow that they paid for the right to put Bruce's work (and PhotoKit Sharpener's output sharpening) into Lightroom. So, pardon me if I dismiss Tom's opinion to a large extent...which, if you notice, is the whole purpose of this thread in the first place...so, at least "some people" disagree with a single sharpen workflow (at least, those who strive to get maximum image quality in prints).
You need to go to school...read his and get back to me: Thoughts on a sharpening workflow by Bruce Fraser