Cults use titles to establish a pecking order. Any level can override the level below, thus insuring control. If Joe Elder steps out of line, he risks the CO coming to town and removing him. If the average publisher drinks too much at a "gathering" he is going to end up in the back room on Tuesday night.
Titles give you instant credibility when meeting new witnesses. If you are and elder or a MS, its going to come up in the first 5 minutes of conversation. It sets the tone as to how high up you are in the corporation.
For women, I imagine its more for bragging rights. All you can really be as a woman is a pioneer, so of course everyone fawns over you because you "sacrifice" by give up time that would be spent working or taking better care of your family. If you don't have the title, others don't really recognize how much you are doing, so what is the point? It really shows that they aren't really "doing it for Jehovah" but rather for the appearance it gives to the other members.