No, you are not the only one, its not about blaming anyone for starting something, but you are the one posting the missions. If you post a mission, and then add the "dont post crap" at the end, your not going to stop the guys that do that, they are going to do it anyway, in fact it probably encourages them. In addition, you might turn away guys that are on the fence and havent made up their mind yet, so that they say "forget it".
Best thing to do is post your missions, and ignore every negative response. Replying only makes you look bad even if you are right and they are wrong.