B)Don't carry often in high heat environments that generate large volumes of sweat.
I don't know that this is an excuse. I mean, I totally understand what you are saying, and it's true that living in a dry climate I don't fully understand what the maintenance routine would be. I haven't had surface rust on any of my guns in, literally, years with the exception of my shotgun, and that was because of rain and snow and long exposure to water.
On the other hand, how is it not neglect? Rust like that doesn't happen instantly nor overnight. Part of carrying a pistol is maintenance, and while I am not casting aspersions on the OP personally, that should have been taken care of immediately. I can't see where S&W has any particular obligation to make things right. Plenty of people carry guns in swampy areas with no problems because they know they just have to do some daily TLC. When my shotgun got surface rust, I wiped it down the first time, learned a lesson about preventative maintenance, and have never had it appear again.
As far as your own pistol rusting, if you are wiping it down, you probably just have salty, corrosive sweat. It happens. I am guessing it didn't happen on your magazine though, and I am further guessing that you had to take daily steps to take care of it. Hey, I might be wrong, maybe the OP is taking care of it and he is just sweating salt and citric acid and it is effecting his gun. In that case, the remedy is a better coating. That takes some cash and is an annoyance, but it is also the cure.