I don't watch women's football, but I think it's probably mainly a lack of pace and power compared to the men's game. I don't know how you would improve it. I would make football a common (boys + girls) sport in primary school so that everyone will develop better technique (at that age the gender difference shouldn't matter so much). Then more girls will play it and be interested in watching women play it, which is probably the biggest issue from the commercial point of view.