Either way, I'm sorry about this whole exchange. Don't be. I appreciate the exchange and very glad you brought up the points you did. If my unnecessary thoughtless generalizations cause harm, they must be questioned.
The author of the Medium post above had some serious questions for me as well. He cared enough about his education to take the time to write me a long email full of challenges. He said he had done that for his teachers in the past and never got a satisfactory response. Like yours, his challenges were thoughtful. For example, he thought the material in my course book were opinions because, while I have a bibliography in the back, I don't provide detailed evidence of the research and sources. I want to focus on activities in the class. I rewrite my course every year and will definitely put in sources throughout the book. Great idea.
I long for students who care enough to challenge me and it takes confidence, courage, and commitment to do that.