Well, that is certainly a valid argument against standards for teachers to carry at school. I'm convinced, well done.
I was going to address the previous version of this post but you changed it...I'll do the best I can based on what I can remember. Please don't confuse my position that all law abiding citizens should be able to carry in schools with the realization that the general population is not ready to allow that. I realize that if any movement is to be made, the first step will be to just get school boards to authorize "somebody" to do it and they will likely place some training and maybe some financial hurdles in the way. I am not, as you accused in your original version an all-or-nothing zealot. If that is the stage through which we must pass in order to remove gun free zones, I'll be all over it.
One of the main points of my posts in this thread is to argue that just because those that are deemed by the powers that be to possess certain qualifications are often less trust worthy than some "untrained" kindergarten teacher. I think this has been a general consensus on this site since I've had an account. But for some reason, in this particular discussion, it seems as though this position has been vacated by some.