I can't believe I'm about to defend Elizabeth (there's always a first), but if her grandfather had a funeral with military honors, it is a VERY impressive ceremony and I'm sure it left an impression on her and everyone there. I have been fortunate enough to have gone to two services like that and what they do is just awe inspiring and unforgettable. I say fortunate because even though it is a funeral and a loss, the military aspect of it is incredible to see.
I don't think she was dissing those that didn't serve. Many didn't serve.
Some can't for medical reasons and some couldn't in WWII and Korea because of either medical reasons or in the case of farmers and other workers, their job at home was deemed necessary for the war effort and they didn't serve.