In my 30+ years of teaching, I've had students from the ages of 11 to 78, but I've never taught children. I have neither the experience nor the expertise to teach children, much less to teach others how to teach children. I could not, in good conscious, agree to teach such a course.
Ironically, my very first major in college was elementary education. That lasted a little over a year. As much as I love children, I couldn't get into the courses, which seemed rather petty to me. I easily got seduced (almost literally) by the Head of the English Department into majoring in English, a major that I later discovered (and was warned by my father) would get me nowhere when I started looking for jobs.
I toyed with majoring in Psychology - and would still like to get a degree in counseling, if I could - but the Psychology Department at my college was pathetic. I'm not sure, for example, that they were familiar with Carl Rogers and Client-Centered Therapy. It was all still Freud and Jung.
I would also have loved to major in Theatre, and took as many courses in the field that I could, but my tuition was being paid by my father, who considered Theatre an even less practical major than English. I defied him later by going on to graduate school and getting an M.A. in Theatre on my own (and with the help of a full-tuition scholarship). It turn out, of course, that my father was right. In fact, neither English nor theatre ever led directly to jobs.
I ended up taking courses in alternative education and finally getting licensed to teach English for senior high, then junior high. That eventually led to my teaching in Japan, where I wasn't able to teach in public junior or senior high schools, so ended up teaching adults, then university.
And, now, at one of the universities where I teach, I've been requested to teach elementary school education. It's so ironic that my earliest major would have been the one to prepare me the best for teaching such a course. But I never would have had the opportunity to teach such a course had I not ended up teaching university-level English.
What really bothers me is that, now that the Ministry of Education has decided English will be required for elementary school children in Japan, universities are scrambling to find instructors to teach courses for future elementary school teachers. Notice that I didn't say qualified instructors. I have been asked, and I'm far from qualified - even with over 30 years experience teaching English and at least 10 years teaching methodology.
No doubt someone will accept the position (and other such positions in universities all over Japan). Are most of those people going to have the qualifications? I have my doubts, and I have even stronger doubts that teaching English in elementary schools in Japan is going to improve the level of English in this country. Not when it's being implemented in such a haphazard way.
If I had continued as an elementary education major, I might have gone on to become an elementary school teacher and, possibly, supervisor. I might even have ended up teaching elementary education. However, I probably would never have come to Japan. So I would have been fully qualified to teach the class that I turned down today, but I wouldn't have been here to be asked!