Probably because historically the patriarchy took away women’s rights to be able to choose mates and had years and years of arranged marriages. Then couple that with women being in those forced relationships who could not chose their partners looking for comfort outside of the inhumane treatment of forced marriages and you get societal pressures that taught women they dont get a say in romantic relationships and as such them showing interest had to be covert as it was typically to those outside their prescribed marriage and if caught they could at the very least be socially disowned or at worst be literally killed for it. So yeah im not surprised women have a tendency to be less obvious about it its only very recently in human history that they got to have a say in finding partners.