Everyone who enters the military, guard or reserve knows they are volunteering to give up certain freedoms, like where to live, how much money they can earn, remote tours without family in areas that might be dangerous, etc.
The problem with Walz is, he's bragging about his service whenever he thinks it bolsters his point. He says he carried the AR-15 in war, yet he's admitted he's never been deployed to any combat zone. He says he retired as a Command Sergeant Major, when he was only in that grade provisionally -- he failed to achieve that rank permanently, and therefore retired as a Master Sergeant, He's claiming to have retired 2 grades higher.
Words matter. And lying with your words when you are a sitting governor of a large state and running for the second highest office in the nation matters significantly more.
Yeah, i get that all politicians lie or exaggerate, but too many good men have sacrificed for our nation to let him lie about the things he did in the Army National Guard for political gain.