I think it's because it's not a shared experience like World War II was. This country clearly prefers those who didn't serve. No veteran has won the presidency since Bush I. Bob Dole was defeated, as were Al Gore, John Kerry and John McCain. Bush II, Cheney and Clinton were all the right age to have been drafted to serve in Vietnam, but they managed not to, like most of those who voted for them. Obama was too young, and so I give him a pass, although he could have volunteered for military service. He did, however, choose not to go for the big bucks as a Wall Street lawyer or investment banker, although he probably could have done that.
Iraq veterans get a lot more respect from the general population than Vietnam veterans did, but that's probably because people feel less guilt about not serving, since there is no draft. But if people were really sincere about the importance of military service, they would serve. They are content to leave it to a certain class, largely middle to lower class, small town Christians. I feel that we went to war in Iraq largely because of Israeli and American Jewish urging. Bush did have issues with his father's Iraq war, but I don't think that his personal issues alone would have let us to invade after 9/11. Jews are prominent in politics, finance, business, but largely absent in the American military, unlike the Israeli military, where people think they are some of the best soldiers in the world. They let Christians die for America; Jews die for Israel. It's strange that defending America comes down to religion or ethnicity. People should consider themselves Americans, regardless of religion, race, or wealth.
Because the American military now comes from a narrow cross-section of the population, it is almost like a mercenary army, unlike World War II. Mercenary armies are typically less successful than armies that are fighting for their homes. America's is sort of a mix of the two. While I come from that narrow cross-section that still constitutes the army, I don't feel that it is a national army or that there is true national support for the troops. Ironically, I think Obama is one of the most sincere supporters and defenders of the troops, unlike a lot of his politician colleagues, particularly flag-waving Republicans, illustrated most recently in their fear over allowing Guantanamo prisoners to be jailed in US prisons.
So, Iraq and Afghanistan veterans, thank you and welcome home, but this country is not really going to do much of anything for you.