Why do you categorize saddles "road" and "touring"?

The terms "road" and "touring" are an attempt to summarize a bike setup and a riding style. A road bike has the handlebars much lower than the saddle. The rider is likely to have an aggressive style. A touring bike would more likely have the bars level with the saddle. A touring rider would be more casual, pacing for the long ride. Of course these are generalizations don't touch the many nuances of each of our riding styles.