They can and do sue the VA regularly though for benefits and medical care, which incidentally, is the same thing these players are suing the NFL for - money for medical care.
I'm not likening the two. In fact, like I said, I think any analogy between military service for our country and any profession is flawed. They're apples and oranges. But if the point is that NFL players are acting entitled by filing suit, I'm just pointing out that vets do it too, and I don't have a problem with either.