I don't disagree with you on much of what you say, but and it's a big but, institute a draft and watch how eager the current generation is to go to war. Remember there were more Americans in Vietnam then there are in the United States Army today. Don't ascribe the patriotism of the men and women in the armed forces to their entire generation until that generation is called on as a group to answer the call. Thus far they haven't been called.
About the draft - as I recall, WWII had drafts and there were few if any protests.
I know, different situation (US attacked vs just going in to clean up the Frenchie's commie mess). But it's not all about a draft.
I stand by the % of dissenters being the main reason for this (think of just how many protests there were for both Bushes' Iraqs; MSM tried to hi-lite them but they were few and not very exciting either, so few stories were even generated).
Any idiot who judges a 50yo as 1 of those "anti-war" idiots because of those latter idiots is just that, an idiot. I don't think many of us judge individuals unfairly based on their group. But we're not afraid to call groups what they are as a whole (or at least all too much).
BTW, I've doubted the patriotism of my own later gen myself. Certainly when you live in MD, it's hard to be convinced. (OOps, another group characterization - but believe me, way too much of MD IS liberal.)