I'm not saying that women are too weak to play 5 sets, just that they should. Serena could play best 9 of 17, no problem. As you say, womens tennis is more popular than mens at this time. There aren't any Americans men at the top of the tennis world. Sooner or later there will be. As far as golf goes mens golf is far more popular than womens. Compare the TV ratings for any major to the ratings for any womens major. If you were a corporate sponsor where would you spend your advertising dollars? And women play on shorter courses and tee off closer than men.