goodgoalie -- I simply don't see the two situations as equivalent. Prize money has never been based on time spent on court, but on number of matches won and/or stage of competition reached.
Theoretically, although exceptionally, it's possible for the winner to spend exactly zero hours on court because their opponents keep retiring with injury before the match starts. In that situation, the lucky beneficiary would no doubt be super-embarrassed to claim their prize money, but they would have "earned" just as much as someone who had needed to turn up to win a match -- and even if you don't extend it all the way to the final, the fact remains that walkover victories still lead to the prize money being awarded for reaching the next stage.
It's a patent nonsense, in other words, to insist that men must perforce get more than women simply by virtue of an average longer match length, regardless of actual circumstances. Or, put another way, I would be OK with the idea of linking money earned to time spent on court, as long as it's applied to every player at a rate that remains equal per hour (or per game/set) for men and women. And once that happens then you anyway would be faced with the situation of players deliberately seeking to draw out matches for longer in order to maximise their possible take.