Not presuming to know the mind of 'old double dots', let me offer my rationale for buying .357M's while fully intent on them never seeing their full ability. It's the sparse nature of the currently available new .38 caliber revolvers. Want a decent .38 plinker from S&W? One example exists, at least with the prerequisite adjustable sights and 4", or greater, barrel: the 67. Go to .357M and your options are many. I was able to get a fine 6" 66, 5" h-l 686+, and PC627 V-Comp over the last 4+ years. They love my .38's - and wimpy .357M's (Mild by .38-44 standards!).
Of course, if the interest were to fade, said .357M has more potential customers, too.
Stainz
.. .. .. .. Where are you??