I think notebooks are neat, and can be a useful tool, especially for learning. But until the last few days I had no clue people were trying to use them for actual software development. To me this is a mistake, and adds a lot of tooling to what was and should be fairly simple process of opening up a text editor (of your choice, mine will be emacs). I am also fairly shocked there is a conference around this idea. I feel that this is a fad and distraction :/. It is a shame so much effort is being spent on this idea as a tool for building software. I think its focus should be on becoming a good aid in teaching people concepts. The last thing I want required to write software is a web browser.
LMAO. Using a notebook with executable code is literally the modern version of Knuth's literate programming.
While I personally don't do much of it, I loved Peter Norvig's python notebooks[1]. Go through one of them and tell me it's not a good aid in teaching people concepts.