American military officers are to be pubilically non-political. They may vote and write letters to their congressman as a private citizen, if they like, just don’t bring their military position into it.
This major did no real service to any cause by asking for accountability of senior leaders. I don’t necessarily disagree with his points, but they are not for public expression by an American military officer. He got something off his chest, that’s all and if he is dismissed from service or resigns, it’s an appropriate outcome.
If he wants to be the next Ollie North, as a civilian, fine. One is too many, though, in my opinion.