Unfortunately i have to agree to a major extend with Harregarre :). I believe that philosophers were more likely to teach males than females, obviously for social reasons. Still :), philosophy has no sex, it is the same for everybody. Sexual attraction therefore is an obstacle to teaching philosophy.
Another reason can be that philosophy, so to say the desire for 'wisdom' , may have been less attractive to women, particularly again for social reasons.
Anyway, philosophy itself has no 'product'. It is the 'vehicle' which journeys science and imagination and its steering wheel is 'ethics', the value which Socrates died for.
Driving without a steering wheel might hurt someone...