Nothing that your son can or can't do should shame you. It's true that they are downsizing the military and maybe he wouldn't have been a good fit anyway. It's not for everyone. My husband served for ten years and you have to basically be ok with some pretty strict rules.
I find this thread interesting. Although I most certainly did not want my oldest son, who could be violently inclined, or my daughter while she was doing drugs to stay at home after 18 (and they didn't last much longer), I wouldn't have cared if my easy child kids had stayed home forever. They were so fun to have around and so easy to live with. Yet one wanted his own place (he is on the autism spectrum) and the other went to college (not too far, but two hours away). I cried both times when they moved out. Now that my daughter who did drugs is clean and sober for years, if she fell upon hard times I would have no trouble letting her and her baby come home for a while because I know she'd pull her weight and because we get along so well and she is not a problem either.
In my house, there was no failture to launch. They launched!! They launched before I was secretly ready...lol.I do miss them. We are still in close touch and I see my son all the time. And...hey...I k ind of enjoy my empty nest. A pleasant surprise!!! If I want to walk around the house naked, I can!!!! My husband can too!!!!! Haha. Just saying...
However, I think that if our adult children are a problem and disrespectful and don't pay rent or help around the house, then, yes, it may be time to launch the rocket...lol. I know that I would not let anyone who made me feel uncomfortable in my home stay in my home.
I hope you can come to a satisfactory conclusion. You don't have to house them forever. "Give them roots to grow and wings to fly."