Putting bombs on target is as dramatic as a mission gets. It requires a gargantuan team effort that is often only as strong as its weakest link. The military seeks to govern its members' sex lives because it knows that otherwise those sex lives can govern the members and threaten missions, large and small. Adultery rules garner public attention, but soldiers live with many intrusive restrictions. In any area near a military installation, merchants know that to get paid by a deadbeat, they need only call the offender's supervisor.
Financial irresponsibility is a careerbuster.
It distracts a soldier from her duties, especially a soldier with a family, and makes her superiors wonder about her judgment. As a young airman, I had friends who, the first of each month, were required to present their 1st sergeant with proof that they had paid their bills. Sometimes a rule is created on the spot by a picky officer who happens to hold a higher rank. It can simply be about perception. As an officer assigned to Turkey, I sought to share an apartment with a male officer in order to save money.