I'm kind of confused by the subject line here? I mean I understand what he is asking but "Why not rear-fanged colubrids" doesn't make much sense to me.......

*sigh* in response to what I think is the question it is because (as Pat and RG already stated) people just do not understand what they are talking about. They hear the word "FANG" and they immediately think of a freakin rattlesnake lunging. What I would do is take a couple of puppy dog tame hognoses in to these dang legislators have them pass them around and then tell them that they are supposedly a rear-fanged snake.
The only thing I've ever heard of happening when someone was bitten by a rear-fanged colubrid was some swelling of the general area and some redness. It takes so much just for them to get their fangs engaged! They have to walk with their front teeth for a while before they can get their rear-fangs in. IDK just my opinion but people fear what they do not know.