@MissAnthrope One time when I was discussing gay marriage with someone who was against it, his reason was, then gay people will abuse the system to become citzens and get health insurance. Can you believe that?! Of course I said back, “so only straight people should be allowed to “cheat” the system.” WTF?!
@all my final answer regarding the OP’s main question is, if it is there for the taking, I’m ok with it, ok with them getting married. Some people get married right before they deploy, because if something happens to them, the spouse will be able to receive whatever benefits a spouse gets when someone dies, and if the girlfriend is going to travel or move with them, better they are married, not only to get moved, but also health benefits, let alone this extra housing allowance. Possibly the allowance for marriage should be changed, but while it is there, I am ok with people using it.
@DrasticDreamer Reasonable question. My father received a housing allowance and he worked for the Public Health Service. He also did not have to change his state residence if he moved. Basically no one lives on a base if they are PHS. For instance the Surgeon General is an officer in the PHS (I think technically a 3 star Admiral or something like that) naval rank and uniform, except the insignia on the uniform is different. They receive full military benefits.