"It's just less cleaning. When I shoot 38 special it leaves a ring in the cylinder that I have to scrub out with a brass brush, or it builds up and makes it hard to load .357. I just figured As long as it was as easy to load one as the, I'd just load some light .357. "

That seems to be conventional wisdom, but I have found it to be false. I shoot very little .357 Mag in my revolvers of that chambering, probably use 99% .38 Special. I always clean the chambers with a wire brush after use, never had the slightest problem with using .357 Mag ammunition, no rings, no residue. Could be true for an extreme high-volume shooter, and I am not in that category.