Men are more inclined to be adventurous when it comes to technology. Most women grew up in a society where tech is a 'guy thing', so it is not very surprising.
Most of the people who are connected to business are always man and because of that, the statistics says that there are more man who are linked to bitcoins rather than woman. Woman are always at home and taking care of the children and i think, that is the number one reason on why there are not that much woman who's an investor of bitcoins.