Not necessarily; very few of the gunfighters tried and stayed with the .38's.(excepting Cody and his .36's) Just like today, cops that are poor shots like lighter guns that don't kick as much. Cops that are smart enough to want to make it home want the bigger, heavier guns, and are willing to carry more mags. . The .38's were smaller and more packable than the peacemakers, and popular with the folks that knew enough to carry a gun when they were traveling or away from town, but rather indefferent to guns.
I guess it can be compared to firemen and regular folks; regular folks have the one crappy little fire extinguisher under the sink because they know they might need it, but they don't care about fire extinguishers; they just have one, but don't even know if it's still charged.
A fireman, on the other hand, probably has several throughout the house of the appropriate rating, but heavier duty, not the 1 lite ones you get at Wally World. He makes sure his family knows how to use them, and regularly checks to make sure they're charged.