The women's are secondary sex organs, the men's aren't.
It is also a clothing perk that men have, when woman have many. For instance men's clothing being dull, uniformed compared to women's, which can also include men's. And, in many office workplaces men must always wear e.g. long pants, shoes and socks. But, women in summer can wear e.g. tank top, shorts and open toed shoes. A man wearing that there more than likely wouldn't still be there.