Because unfortunately gender matters when trying to raise money to start a business. Investors factor it in to their investment decisions. Sometimes they do it on purpose (i.e. Are you going to have kids? Will men in ___ industry take you seriously to do deals with or want to join your team? If I give her money, will she sleep with me?) and sometimes they don't do it on purpose (i.e. Misgivings of whether she can "lead", "be tough", manage money, take risks. More doubts than a man with similar or lower credentials).

Last I read something like 97% of venture funding goes to men. 57% of bachelors degrees are earned by women. So it's not like there is a lack of women who can set and accomplish long term goals and manage money.