Double Action speed and/or accuracy-
Tell Ed McGivern he's wrong.
5 shots
15 feet
2/5 of ONE second
covered with a playing card
with a LONG action S&W.
Tell Jerry Miculek he is wrong when he does 12 in less than 3-
World Record 12 Shots In Under 3 Seconds - YouTube
Depends on what you practice doing. I am NOT anywhere close to the ability of the above shooters, but I came along at the height of PPC shooting, which is all DA. Yeah, yeah, I know they used tricked out bull guns with buttery soft actions. BUT, you could also shoot the course with a Mod 27 and magnum ammo, at least informally. It'll teach you a bit about DA shooting.
In my 30's, I could hit a small galvanized well tank, EVERY shot, at 200 yds, DA. I have hit 2 rams with 3 shots on a silhouette course, DA with a stock Mod 29, STANDING, two hands.
When I go to my barn and a squirrel, possum, or coon runs out, I engage it with my carry gun. I have not fired at one yet that lived. Some make the brush and get away, but some climb a tree. Some don't make it to brush or tree.

Carry gun is a 642, so there ain't no hammer to cock.
For the record- +P's WILL kill, squirrels, possums, and raccoons.
Do I shoot SA? Of course I do.
That doesn't mean I did not learn to shoot effectively DA.
BTW-
have NOT read the article.
Don't know what it said, but every shooter should be taught to shoot DA. Every shooter should be taught the inherent advantages/disadvantages of both schools. People who will never spend the time and effort to get very familiar with guns should be taught with a lot of emphasis placed on the inherent accident potential of cocking a gun and handling a cocked gun under extreme stress.