I think I understand the thought process behind it even though I don't own any pinned barrel S&W's. As an example, I believe the older German-made SIGs with the carbon steel slides and pinned breach blocks are much higher quality and better performing than the new US-made versions with one-piece machined stainless steel slides. I've had P226's of both styles and the older gun was hands down a better performer.

On the other hand, newer can sometimes be better as well. I find the new slab-sided barrels with tapered underlugs/ ejector shrouds found on the new Pro Series Smiths to be so aestheticaly appealing, that I doubt I'd ever buy another revolver without that barrel style again.