Because they will never have to pay with their blood for electoral folly. It's the guy who writes the check that gets to decide how the money is spent. When the age of majority is attained in this country, men must hand over a blank check to the federal government or face 5 years in prison and/or a $250K fine. A great many other penalties attach as well.
I don't doubt the competence, courage, or patriotism of many women. I have significant misgivings about their understanding of the use of force, and that's precisely what government is - force. If you don't understand how/when it is appropriate to use force, and have the capacity to actually employ force, you have no business deciding the manner and timing of its use.