I have a couple of revolvers, a Smith M65 and a Colt Trooper, both are really nice and crisp in single action. Even in double action, the pull is still very nice and with clean break.
Personally, I've not found it categorically true that revolver triggers are better than semi-auto. To me, the triggers of the 2 platforms are simply different, and there are plenty of good and bad examples of each.
In most revolvers, the sear is part of the trigger and interfaces directly with the hammer. In most auto pistols, the trigger interfaces with a trigger bar, which contacts the sear, which interfaces with the hammer or with a striker. All of these parts have clearances made necessary by the way they need to operate. The result is that even though a lot of the "slop" can be taken out, some must remain for safety and reliability.
I'm assuming Jim is referring to a revolver's
SA mechanism. That the sear interfaces directly with the hammer may also be technically true in DA, but there are a whole bunch of other interfaces that contribute to DA trigger quality, e.g. rebound slide/frame, rebound slide/trigger, hammer/frame, trigger/hand, hand/cylinder interface, etc, etc. From the factory, it's unlikely all these interfaces are perfect, so there's likely quite a bit of "slop" and roughness that can make a revolver trigger feel "like a stick being pulled along a picket fence".
I get the impression that some feel a trigger job is simply a matter of installing lighter springs, a little honing and dry firing the batsnot out of it. My suspicion, though, is that good revolver 'smiths instead spend a good deal of time smoothing each one of these interfaces.
No offense, but I think my part of the country is more mainstream than wherever you're finding all the folks using cocked double actions. All the growth seems to be in timed competitions of one type or another.
Another way to say it, is that competition's getting popular, so many compete with a revolver. And if you compete with a revolver, it'll likely be some form of combat action type shooting, shot in DA. True enough, but the thing is, most I see at the range aren't mingling with competitive shooters, and seem fairly uninfluenced by them.