Airing down the tires is certainly an appropriate method to increase traction, but with something like the S10, there really are some factors you have to consider when you do it. It's not quite the same as letting air out of the tires of a CRF250.
Our bikes are easily 700 plus pounds when you consider the wet weight plus all the doodads we tend to attach to them. Put a rider on it who, when geared up, weighs anywhere from 220 lbs up to 300 +lbs, and you have upwards of a half ton of vehicle. Couple that with the types of 80/20 radials many of us ride, with thinner sidewalls than something like a K60, and some really rocky terrain, and you probably have a pretty slim margin for error when it comes to rim damage.