They would probably make more money on ad time
The current deal with USA network (Raw) involves USA paying WWE a flat 500,000 approximately per week, and USA deals with the advertisers. I am not sure how Smack, ECW, and Superstars are done.
Thats why in the old days of wrestling you wouldn't see the world champ headlining every single episode.
I still do not like seeing the champ introduced first, but that has been a really long time since being respected.
Good point about the midcarders, tag and IC. Also, included is the fact that people like Demolition holding the titles over a year, HTM holding the title over a year, Hogan and Macho WM4 and WM5 holding the title for a year each, makes it a "bigger" piece of drama.