After 1000's of years it has always been the job of the man to propose, however is it due to the change in society that it is now sociably acceptable for a woman to propose on this day?
If you love someone with all of your heart it shouldn't matter which person in the relationship decides to pop the question. Either one or the other would decide under circumstances they couldn't control. The force of love on ones heart. The want to spend your life, day in day out, with the same face to wake up to every morning.
Even if society has changed and this isn't the woman's job then this day gives them the chance to open up and let out their feelings to the person in the world that they love the most.
If they know, deep down, that this person is the one... that they will love them forever and that they will say yes then why wait?
Will you marry me? I wonder.