Injuries are a big problem for *both* the ATP and the WTA. Therefore, it would be much more logical to shorten the men's Grand Slam tournament matches and Davis Cup matches to best-of-three sets, than to lengthen women's Grand Slam matches to best-of-five sets.
As far as men getting more spectators and TV, I've seen no evidence that the women are less viewed than the men. Post a serious link that proves what you're saying.
Billie Jean King, Margaret Court, Gladys Heldman, and many others struggled for a long time to get equal pay. Don't expect them to give up what they've earned.