They don't think of service like that. The main important takeaway of military service for many is structure in your life (often a first for many), a feeling of brotherhood (often a first for many), and a tangible set of goals in life (often a first for many). The killing machine part is an abstraction that is easily ignored. After all, you're ultimately killing people that hate America, and that is obviously "a good thing."

Replace the brotherhood with a set of people with very different beliefs that ultimately wouldn't support each other and give them a mandate to work together to fight a common enemy. It just won't work that well.

That's probably what GP meant about the problems of woke.