Teaching also involves stating an idea - which the author forgot to actually do. If it is your article that I am criticizing, I’m sorry for being crass, but make no mistake, the writing is half-assed. An article whose primary piece of advice is to “focus on the datatypes”, shouldn’t avoid the word “datatype” until the 2nd to last header.
Truthfully, the article would be better served by removing the first and 2nd to last section and instead be titled “Why I dislike working with monads in languages that support monads.”