I've not been one to condemn those who served in the American military, even when they were in wars that I thought were foolish and wrong.
I've always thought that stories of soldiers coming home from Vietnam and facing hostility from fellow citizens ("spitting on them in the airport" for instance) were more fanciful than factual. This is perhaps because I don't know anyone who would do that, even though I do know (or have known) people who think war is folly -- and particularly some of America's wars like Iraq and Vietnam.
I can't accept that average GI Joes who went to war, satisfied in their minds that they were serving the country and making it safer, ought to be considered deserving of contempt. It was other people who made those decisions and judgments, and other people who should be held to answer.
So I do think of Memorial Day as a worthy holiday and its military worthy of high regard.