Have you ever actually tried to teach someone who doesn't know how to program? It takes months, even when using a simple language like Python. Or even BASIC, which was designed specifically for beginners.
Standard ML is a good language (especially considering when it was developed, in the 1970s). Somehow a cult has grown up around it that prevents people from seeing that it isn't the solution to all problems, just another tool in the toolbox. Sad.