I'm not clear on what the argument here is. Are current assault rifle regulations bad? Yes, clearly. But they didn't start out that way; most centerfire semi-automatic rifles that accepted detachable magazines would have been (properly) considered assault rifles under the original 1980s proposals. (The AR-15 itself, of course, was designed by Eugene Stoner to be a standard-issue US military rifle.)
The only thing I think we can conclude about the incoherence of firearms legislation is that they have staunch and effective opposition from firearms advocates. I do not think it is at all valid to look at them and say "legislators don't know what an assault rifle is".
The only thing I think we can conclude about the incoherence of firearms legislation is that they have staunch and effective opposition from firearms advocates. I do not think it is at all valid to look at them and say "legislators don't know what an assault rifle is".