Well, Heather, I agree that you can't speak of something only someone in the military would know about, such as what it's like to be in a firefight, but there are some things about the military that non-members can talk about because you don't need actual experience to know of them. Many people who aren't in the military know of the tests, that military service involves being shipped overseas, and other obvious things.
Your logic implies that anyone younger than 74 can't talk about the start of WWII since they weren't alive to see it. No one has absolute experience in the world, so to say that you need it to talk about anything means that you wouldn't be able to talk about much at all. After all, Barrack Obama is the commander in chief. He never served in the military, but now he's its leader. By your logic, he would need to be stripped of that title.
PS--> What's ironic is that Beck had something he said taken out of context. He wasn't mocking female soldiers as "Transgender breast cancer survivors." He was making an exaggerated point that regardless of how unique someone is, diversity shouldn't be a factor in military selection, even if that person is a "female, Hispanic, Eskimo... transgender breast cancer survivor." He wasn't calling all female soldiers that. He was stating that diversity doesn't make for a good military; properly trained, fit, killing machines do that.
He definitely needs to work on his deliveries, but he still makes valid points in this case, regardless of how jerky he comes across as.
