OK, I'm very new to these forums, but I've posted in several other forums (a local one, a gaming one, and several professional ones) for years. I'm guessing you folks have been burned badly recently by folks passing themselves off as something they aren't, although I'm not sure how that could become that much of an issue. We've had no-it-alls who don't in other posts, and they were fairly soundly shut down by true experts who simply exposed them for what they are.
It seems obvious that many of you all know each other well, at least through these forums, and you're active enough to know newbs like me from regulars. A newb that starts sounding fishy can be checked out with some direct questions and chucked out if they fail.
If you only want military folks posting here, just say that. If the problem is simply folks spouting off about things they don't know about, well, that form of expression certainly isn't limited to non-military folks. My experience in the US Army, Kansas National Guard, and civilian life have led me to believe that a wide range of thoughts and ideas makes for a much better discussion.