They're not interested

Lt. Smash and some soldiers try to engage Code Pink protesters outside Walter Reed hospital.

SMASH: Had you identified yourselves as soldiers from Walter Reed?

P.D.: Oh, yeah...

Mason: Oh, yes sir. We had told them all about our background. I served in Iraq. He served in Afghanistan and Iraq. We were patients at the hospital. That we were just curious... But that did not seem like a good answer to them.

P.D.: We tried to explain to them that we were fighting for freedom. They said "no."

Mason: And then they basically told us that if we weren’t there, the terrorists wouldn’t be there. And that the terrorists, you know, even though the terrorists murder civilians, and children, that if we left it would all... stop. And I... I literally saw, with my own eyes, families be executed by ‘em. And I don’t think it would matter if we were there or not. The terrorists are terrorists. That's what they do.

P.D.: It’d be a lot more people getting executed if we weren’t there.

SMASH: Did you try to express any of that to the folks down there?

Both: Yes, sir.

SMASH: And how was it received?

P.D.: It was received negatively. They were closed-minded. They have their beliefs, and they won’t even open their minds to what we believe.
[Emphases in the original.]

I suppose Smash et al think that it's useful to expose the "we support the troops but not the war" protesters, but personally I wouldn't even bother.

Via Instapundit.