Running a Bash kernel in Jupyter Notebook might be convenient if you are running your Jupyter server on a remote machine. So you don't have to SSH into the server for some quick changes, you can stay in your browser. I haven't used it myself as I only use it locally.

So actually the main reason I'm interested in ipython-style notebooks for my terminal shell needs is the benefit of having... graphs! and pictures! and other graphical things in a terminal shell setting. I'm willing to put up with inconveniences you speak of if I can get the graphical things working well. People have experimented with it, it seems: http://jeroenjanssens.com/2015/02/19/ibash-notebook.html I'll look more into it now.

Only for expository processing, keeping things transparent for people who are not necessarily programmers. Still waiting for spell checking in markdown blocks