MyMaths MyLife

In my experience, main reason is "The Fear Factor".

The first is, because the feelings of inferiority and outright fear that many, probably most, students feel when they confront mathematics, severely inhibit students’ natural intelligence and creativity. It is as though every mathematical subject, and every concept within a subject, is surrounded by a kind of “force field” that radiates, “Not for you!”, “You aren’t smart enough!”. The origin of this force field may be early experiences in a family in which, say, a father had always been good at mathematics, and had made it clear he expected his children to likewise be good at the subject. In the case of women, the origin might be subtle messages sent by teachers through out the primary and secondary school years — perhaps without conscious intention — that technical subjects are too hard for girls. Or, it might be the atmosphere that surrounds mathematics and indeed all technical subjects in the nation’s most schools.