I think of it from the logic point of view (If you disagree with me, please tell me and discuss it).
Girls and Women are a little bit much more than boys and men, that's why there is more websites for women than for men.That's one.
The second, women, usually wives and girl friends and even single girls, tend to spend more money than men. This means that their purchasing power is a little more than men, so if you are starting a new business, you will look to target the people who have the most purchasing power to make sure that you are going to sell.
Just have a look at the businesses out there serving women. Make ups, Avon and the likes, Dressing? Fashion? Plastic Surgeries? Shoes?? Panties?? Look at the advertising of the underwears and compare how many ads for the women underwears compared to ads of the mens underwear??? You will probably find the same ratio you found for the websites.
Thirdly, not all women work, so many of them have spare time, which they will spend over the internet. Men spend most of their time over the internet at work and searching for issues related to work, while women will likely search for beauty, fitness, etc... So the probability of a succesull website for women is more than a website for men or boys.
Fourth, fitness for example and weight loss is much more important for women than it is to men. Same applies for beauty and make up shops. Then you will likely have a successfull website dedicated to women rather than dedicating it to men.
That's just some thoughts off my mind
